Ovid Technologies Field Guide

NHS Economic Evaluation Database (CLHTA)

The Evidence Based Medicine Reviews Collection

Table of Contents:
Scope | General Information | Searching the Fields | Advanced Searching | Limits
Tools | Changing to this Database from Another Database | Copyright Information | Updated

Scope

Evidence Based Medicine Reviews Collection

A patient asks a clinician, "Does vitamin C prevent the common cold? Are there effective therapies to treat a cold once you have one?" Although these questions are common, they are not always easy to answer. Medical knowledge is advancing rapidly, and the literature that reports new findings is expanding by almost half a million articles every year.

In the past, a clinician might seek answers to these questions within a textbook. But textbooks are updated infrequently, only every 3-5 years. And a new, definitive study might be published in today's medical journals, but not appear in the most recent textbooks.

The clinician might call an infectious disease specialist. But specialists are very busy, and may not have time to answer such questions.

The clinician might perform a traditional search in a medical database, such as MEDLINE. Unfortunately, a search using the MeSH term "common cold" yields over 1,400 articles written in the last 30 years. Finding a relevant article might take as long as 30 minutes or more.

But today, with Ovid's Evidence-Based Medicine Reviews (EBMR), answering clinical questions is a whole lot easier. Using Ovid's MEDLINE, a clinician can enter the term "common cold," select the EBM Reviews limit, and in seconds, a small number of high-quality articles appear that discuss prevention and treatment of the common cold.

Some of the articles retrieved have met rigorous inclusion criteria by the international Cochrane Collaboration, and then have been used as the basis for a systematic topic review. Clicking on the Topic Review link retrieves the Cochrane Review "Vitamin C for the Common Cold" which analyzes and synthesizes over 30 of the best clinical trials on the subject.

Other articles in the result set have been the subject of an evidence-based article review by the editorial staff of Best Evidence (a joint project of the American College of Physicians and BMJ Publishing Group) or by the National Health Services (NHS) Centre for Reviews and Dissemination at the University of York, England. Clicking on the Article Review link retrieves the enhanced abstract of the article together with commentary about the article's relevance to clinical practice.

So, the result from using Ovid's EBMR: the most comprehensive answer in less than a minute. EBMR helps clinicians to find the best answer to clinical questions in the least amount of time.

CLHTA

Produced by the Centre for Reviews and Dissemination (CRD), the Health Technology Assessment database brings together details on ongoing health technology assessments (studies of the medical, social, ethical, and economic implications of healthcare interventions).

HTA is produced in collaboration with the INAHTA Secretariat, based at SBU, Sweden. The database contains records of ongoing projects being conducted by members of INAHTA as well as publications reporting completed technology assessments carried out by INAHTA members and other health technology assessment organizations.

The abstracts in the database are descriptive rather than analytical and do not provide critical appraisals of the reports, as the reports have not been evaluated by reviewers from the Centre for Reviews and Dissemination.

Many different types of research are included in the HTA database, including systematic reviews and ongoing and completed research based on trials, questionnaires and economic evaluations. In some cases there will be an overlap with systematic reviews in the Database of Abstracts of Reviews of Effect (DARE) database and economic evaluations in the National Health Service Economic Evaluation (NHS EED) database.

More information on this database is available from the CRD: http://www.york.ac.uk/inst/crd/hfaq.htm

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General Information

Producer
      The Cochrane Collaboration
Home Page: http://www.cochrane.org
Segments
  CLHTA
  This database does not support Ovid's AutoAlerts. If you want to create a reusable search strategy, save the search as a Permanent Saved Search instead. See the Ovid Web Gateway User Manual for details about permanent saved searches. Saved search information also appears in the Ovid Web Gateway Help System.
All Fields Display/Print Fields
  Accession Number (AN) Language (LG) Source (SO)
  Author’s Conclusions (AC) Local Messages (LM) Study Design (SD)
  Authors (AU) Publication Type (PT) Study Information (IF)
  Copyright (CO) Record Status (ST) Subject Headings (SH)
  Correspondence Address (AD) Reviewed Article Authors (AY) Summary Language(SL)
  Country of Publication (CP) Reviewed Article Editors(ER) Title (TI)
  Database Entry Date(CY) Reviewed Article Publisher (RP) URL (UR)
  Digital Object Identifier (DO) Reviewed Article Year of Publication (DI) Year (YR)
  ISSN (IS) Reviewed Source (SR)  
Default Fields for Display/Print Fields
  Accession Number (AN) Language (LG) Source (SO)
  Author’s Conclusions (AC) Local Messages (LM) Study Design (SD)
  Authors (AU) Publication Type (PT) Study Information (IF)
  Copyright (CO) Record Status (ST) Subject Headings (SH)
  Correspondence Address (AD) Reviewed Article Authors (AY) Summary Language(SL)
  Country of Publication (CP) Reviewed Article Editors(ER) Title (TI)
  Database Entry Date(CY) Reviewed Article Publisher (RP) URL (UR)
  Digital Object Identifier (DO) Reviewed Article Year of Publication (DI) Year (YR)
  ISSN (IS) Reviewed Source (SR)  
Elements of the Source (SO) Field
  Issue/Part (IP) Publisher (PB) Year of Publication (YR)
  Journal Name (JN)    
Elements of the Reviewed Source (SR) Field
  Reviewed Article Authors (AY) Reviewed Article Journal Name (SJ) Reviewed Article Volume (DV)
  Reviewed Article Book Chapter (CH) Reviewed Article Page (PR) Reviewed Article Year of Publication (DI)
  Reviewed Article Editors (ER) Reviewed Article Publisher (RP)  
  Reviewed Article Issue/Part (PO) Reviewed Article Title (TO)  

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Searching the CLHTA Fields

The following list is sorted alphabetical by field alias. Click a field name to see the description and search information.

Field Name Label   Field Name Label
Author's Conclusions AC   Publisher PB
Correspondence Address AD   Publication Date PD
Accession Number AN   Reviewed Article Issue/Part PO
Authors AU   Reviewed Article Page PR
Reviewed Article Authors AY   Publication Type PT
Reviewed Article Book Chapter CH   Reviewed Article Publisher RP
Copyright CO   Reviewed Article Journal Word RW
Country of Publication CP   Study Design SD
Database Entry Date CY   Subject Headings SH
Reviewed Article Year of Publication DI   Reviewed Article Journal Name SJ
Digital Object Identifier DO   Summary Language SL
Reviewed Article Volume DV   Source SO
Editors ED   Reviewed Source SR
Reviewed Article Editors ER   Record Status ST
Floating Sub-Heading FS   Subject Code SU
Subject Heading Words HW   Title TI
Study Information IF   Text TX
Issue/Part IP   Update Flag UF
ISSN IS   URL UR
Journal Name JN   Catalog Holdings XH
Journal Word JX   Exploded MeSH Heading XM
Language LG   Exploded Sub-Heading XS
Product Online Date OD   Year YR

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The following list is sorted alphabetically by the two-letter label, and includes the relevant alias, at least one example for all searchable CLHTA fields, and a description of the field.

Label Name / Example
AC Author's Conclusions [Word Indexed]
economic benefit.ac.

The Author's Conclusions (AC) field summarizes the author's conclusions about the study and its results. 

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AD Correspondence Address [Word Indexed]
macarthur.ad.
university of utah.ad.

The Correspondence Address (AD) field contains the contact information associated with the authors of the document.

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AN Accession Number [Phrase Indexed]
cmr-10682.an.

The Accession Number (AN) field contains a unique number which identifies a record in the Cochrane Methodology Register.  All accession numbers are preceded by the letters "CMR."

Additionally, if the record has been newly added since the last database update, the Update Flag (UF) "NEW" will display after the accession number. Search new.uf. to retrieve all of the most recently added citations.

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AU Author [Word Indexed]
raynor td.au.
mann$.au.

The Author (AU) field includes the name of the group or individuals who authored the document.  The author field is indexed in the format of last name followed by first and middle names or initials, as they appeared in the original article. Thus, a person named James Charles Smith may appear as Smith James C, Smith J. Charles, Smith JC, or Smith J. Note that editor names will display in a separate field from the author names.

To search the index, enter the last name. If you are unsure of the spelling of the last name, enter one version. You will be able to scroll through the list of names to find other spelling variations.

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AY Conference Date [Word Indexed]
hagan.ay.

The Reviewed Article Author (AY) field contains the names of all the authors of the article or study being reviewed. 

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CH Reviewed Article Book Chapter [Word Indexed]
decision analysis.ch.

The Reviewed Article Book Chapter Title (CH) field includes, if applicable, the chapter title of the book in which the reviewed article was published.  This field displays as part of theReviewed Source (SR) field.

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CO Copyright [Word Indexed]
university of york.co.

The Copyright (CO) field contains the copyright information associated with an article.

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CP Country of Publication [Phrase Indexed] 
ireland.cp.

The Country of Publication (CP) index contains the full name of the country in which an article was published. 

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CY Database Entry Date[Phrase Indexed]
2002.cy.

The Database Entry Date (CY) field contains the year in which the article was added to the database.

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DI Reviewed Article Year of Publication [Phrase Indexed]
2003.di.

The Reviewed Article Year of Publication (DI) field includes the year of publication of the reviewed article. 

This field displays as part of theReviewed Source (SR) field.

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DO Digital Object Identifier [Phrase Indexed]
10.1002/14651858.do.

The DOI (DO) field contains the Digital Object Identifier - a unique and persistent digital identification code for any object of intellectual property.

The DOI itself consists of two parts: a prefix which is assigned to each publisher by the administrative DOI agency, for example "10.1002", and a suffix which is assigned by the pub lisher and can be any code that the publisher chooses, such as "14651858". The full DOI appears as such: "10.1002/14651858".

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DV

Reviewed Article Volume[Word Indexed]
"63".dv.

The Reviewed Article Volume (DV) field includes the volume of the reviewed article. This field displays as part of the Reviewed Source (SR) field.

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ED Editors [Phrase Indexed] 
centre for reviews and dissemination.ed.

The Editor (ED) field contains the editor(s) associated with the article.

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ER Reviewed Article Editors[Phrase Indexed]
sibinga.er.

The Reviewed Article Editors (ER) field includes the editors of the reviewed article. This field displays as part of the Reviewed Source (SR) field.

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FS

Floating Sub-Heading [Word Indexed]
therapeutic use.fs.

Subheadings are qualifiers added to MeSH subject headings to refine their meaning.  Terms such as "etiology" or "therapy", when combined with a MeSH heading, give a precise idea of what an article covers.

The Floating Subheadings (FS) field contains both the 2-letter codes, such as "po" and the full headings, such as "poisoning". These are displayed following the corresponding MeSH Subject Headings.
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HW Subject Heading Words [Word Indexed]
bipolar.hw.

The Subject Heading Word (HW) field allows you to search for and retrieve every MeSH Subject Heading (SH) and Publication Type (PT) that includes a particular word. 
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IF Study Information  [Word Indexed]
primary prevention.if.

The Study Information (IF) field contains general study information such as effectiveness analyses, study population, and cost and funding information.

This field can also be searched as part of the Text (TX) field.

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IP Issue/Part [Word Indexed]
"3".ip.

The Issue/Part (IP) field includes the issue associated with the current NHS-EED database.  Because the nature of the database is to be continually updated, the issue associated with each abstract will change with a new release of the database.

This field displays as part of the Source (SO).

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IS ISSN [Word Indexed] 
1465-1858.is.
The ISSN field (IS) contains the International Standard Serial Number for the journal in which the document was published.
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JN Journal Name [Phrase Indexed] 
nhs economic evaluation.jn.

The Journal Name (JN) field contains the full name of the journal in which the article was published.

This field displays as part of the Source (SO).
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JX Journal Word [Word Indexed]
economics.jx.

The Journal Word (JX) field contains individual words from every journal name. 

This field displays as part of the Source (SO).

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LG

Language  [Phrase Indexed]
english.lg.

The Language (LG) field contains the language(s) of publication of the reviewed article.  The language name is fully spelled out.

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LM Keywords [Word Indexed]
cmr bias in trials blinding general.kw.

The Local Messages (LM) field contains messages created by your Ovid System administrator to indicate holdings information about journals held in your library or institution.s

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OD Product Online Date [Word Indexed]
2006.od.
The Product Online Date (OD) field contains the date of the initial release of NHS EED.
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PB Publisher [Word Indexed]
wiley.pb.
The Publisher (PB) field includes the publisher name for an article.  This field displays in the Source (SO) field.
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PD Publication Date [Word Indexed]
2007.pd.
The Publication Date (PD) field contains the publication date code for the current issue of NHS-EED.
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PO Reviewed Article Issue/Part  [Word Indexed]
"5".po.

The Reviewed Article Issue/Part (PO) field includes the issue and supplement number in which the reviewed article was published. 

This field displays as part of the Reviewed Source (SR) field.

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PR Reviewed Article Page [Word Indexed]
"3".pr.

The Reviewed Article Page (PR) field includes the page number of the reviewed article. 

This field displays as part of the Reviewed Source (SR) field.

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PT Publication Type [Phrase Indexed]
review.pt.

The Publication Type (PT) field describes a document's overall form and substance in broad categories.

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RP Reviewed Article Publisher [Word Indexed]
kluwer.rp.

The Reviewed Article Publisher (RP) field includes the publisher of the reviewed article. 

This field displays as part of the Reviewed Source (SR) field.

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RW Reviewed Article Journal Word [Word Indexed]
transfusion.rw.

The Reviewed Article Journal Words (RW) field contains individual words from every journal in which a reviewed article was published.

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SD Study Design [Word Indexed]
retrospective.sd.

The Study Design (SD) field is defined (for example, randomised controlled trial or cohort study) and the number of centres is stated along with the duration of follow-up of the treatment cohort. If it is an experimental study,the participant allocation method is described, for example the block randomisation or stratified allocation.

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SH MeSH Subject Headings [Phrase Indexed]
infusion pumps.sh.

The MeSH Subject Headings (SH) field contains the Medical Subject Headings used by indexers at the National Library of Medicine (NLM) to describe the content of an article. NLM's MeSH terms are organized in a hierarchy, or "tree" structure.

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SJ Reviewed Article Journal Name [Word Indexed]
american journal of obstetrics and gynecology.sj.

The Reviewed Article Journal Name (SJ) field contains the full name of the journal in which the Reviewed Article was published. 

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SL Summary Language [Word Indexed]
english.sl.

The Summary Language (SL) field contains the language or languages in which the article is written.

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SO Source [Word Indexed]
new england journal of medicine.so.
france.so.

The Source (SO) field provides a display of all the basic information needed to locate a citation, including the full Journal Name (JN), Publisher (PB),  Issue/Part (IP), and Year of Publication (YR), (if they exist).

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SR Reviewed Source [Word Indexed]
"2006".sr.
obstetrics.sr.

The Reviewed Source (SR) field includes the complete bibliographic citation(s) for the publication(s) being reviewed.  These references can be viewed with the citation or with the full text.

The Reviewed Source field is word indexed.  To search, enter the desired reference information, consisting of words typically found in a reference.  Consider searching for words in the document title, journal name or abbreviation, author name, page number or year.

If you know the specific type of information you are seeking (such as a document title), you may also choose to search in one of the following fields: 

Reviewed Article Authors (AY)   Reviewed Article Journal Name (SJ)   Reviewed Article Volume (DV)
Reviewed Article Book Chapter (CH)   Reviewed Article Page (PR)   Reviewed Article Year of Publication (DI)
Reviewed Article Editors (ER)   Reviewed Article Publisher (RP)    
Reviewed Article Issue/Part (PO)   Reviewed Article Title (TO)
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ST Record Status [Word Indexed]
evaluated.st.

The Record Status (ST) field contains the status of the article as reported by the CRD.

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SU Subject Code [Word Indexed]
MD00.su.

The Subject Code (SU) field contains a subject code assigned by CRD. 

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TI Title [Word Indexed]
economic assessment of platelet glycoprotein.ti.

The Title (TI) field contains the title of the NHS-EED record, which generally corresponds to the title of the Reviewed Source as well.
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TO Reviewed Article Title [Word Indexed]
alternative approaches to human blood resources.to.

The Reviewed Article Title (TO) field contains the title of article being reviewed. 

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UF Update Flag [Phrase Indexed]
new.uf.

The Update Flag (UF) field contains "New" if the review has been newly added since the last database update.  If the record has not changed since the last update, there will be nothing in this field.

Search new.uf. to see all of the reviews which have been added since the last update of the database.
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UR URL  [Word Indexed]
elsevierhealth.ur.

The URL (UR) field contains the URL information for the original article.

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XH Catalog Holdings [Display Only]

The Catalog Holdings (XH) field indicates (with a "Y" or an "N") if a journal is held locally.
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XM Exploded MeSH Heading [Phrase Indexed]
.xm.

The Exploded MeSH Heading (XM) field contains pre-exploded MeSH Headings. MeSH Subject Headings are hierarchical, with up to twelve levels of narrower terms from the top of a hierarchy. In order to retrieve a term and all of its narrower terms, a subject heading must be "exploded", that is, the subject heading and all narrower terms are "OR'd" together. OVID pre-explodes highly-posted broader terms with their narrower terms during loading. These pre-exploded MeSH Headings are displayed in the MeSH Subject Headings (SH) field.

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XS Exploded Sub-Heading [Phrase Indexed]
.xs.

The Exploded Subheadings (XS) field contains the two-letter codes for the pre-exploded subheadings. Sometimes multiple MeSH Subheadings can be logically grouped together.  Such related groups of subheadings are "pre-exploded" under one broad subheading.  This means that all the grouped subheadings can be retrieved together by searching on the "pre-exploded" version of the broad subheading. These pre-exploded MeSH Headings are displayed in the MeSH Subject Headings (SH) field.

The Exploded Subheadings (XS) field contains the two-letter codes for the pre-exploded subheadings. Sometimes multiple MeSH Subheadings can be logically grouped together.  Such related groups of subheadings are "pre-exploded" under one broad subheading.  This means that all the grouped subheadings can be retrieved together by searching on the "pre-exploded" version of the broad subheading. These pre-exploded MeSH Headings are displayed in the MeSH Subject Headings (SH) field.
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YR Year of Publication [Phrase Indexed]
2005.yr.

The Year of Publication (YR) field contains the year in which the article was published.

This field displays as part of the Source (SO).

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Advanced Searching

You can use special words and symbols to combine search terms and refine a search. For efficient searching, use the most appropriate operator from the list below to combine search terms. For more information on these and other searching techniques, including command line syntax searching, refer to the Ovid Gateway Help.

Operator Syntax Example Results
OR OR vitamin c or ascorbic acid Retrieves records that contain either term or both terms.
AND AND vitamin c and ascorbic acid Retrieves records that contain both terms.
NOT NOT vitamin c not ascorbic acid Retrieves records that contain the first term but not the second term.
ADJ ADJ autism aspergers Retrieves records that contain both terms, in order, and adjacent in the same sentence.
  ADJn autism adj3 aspergers Retrieves records that contain both terms, in either order, with no more than n number of words between. The example will retrieve records containing the phrase, "adults with autistic and Asperger's disorders".
FREQ x.fd./FREQ=n blood.ab. /freq=5 Retrieves records that contain n occurances of the term in the specified field. The example will retrieve records containing the word "blood," at least five times in the Abstract (ab) field.
$ x$ rat$

The unlimited truncation symbol, $, retrieves records that contain the search term and all possible suffix variations of a root word. The example will retrieve records containing words such as rat, rats, rate, rationalize, ratify, etc.

  x$n dog$1 The limited truncation symbol, $n, Retrieves records that contain the search term and all possible suffix variations of a root word with the maximum number of characters that may follow the root word or phrase, specified by n. The example will retrieve records containing words such as dog and dogs, but not dogma.
 #  # wom#n The mandated wildcard symbol, #, retrieves records that contain the search term with substituted character(s) in the specified locations. The example will retrieve records containing woman and women.
?  ? colo?r The optional wildcard symbol, ?, retrieves records that contain the search term with either no characters substituted, or with substituted character(s) in the specified locations. The example will retrieve records containing color and colour.

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CLHTA Limits

The following limits are available from the Limit menu on the Main Search Page.

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Changing to this Database from Another Database

Command Syntax: ..c/clhta
Sentence Syntax: use clhta

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CLHTA Producer Copyright Information

The materials contained herein are proprietary to the publishers and/or individual copyright holders and may only be used by authorized users of the subscribing institutions for internal or personal research. Authorized users may (i) print data obtained from searches and make limited copies of such printed search results, (ii) download data obtained from searches and (iii) retransmit search results electronically or otherwise to a limited number of authorized users at the same institution. Authorized users are precluded from: (i) copying, duplication, redistribution, retransmission, publication, transfer or commercial or other exploitation of the databases or the contents thereof, except as permitted herein or pursuant to user guidelines of the individual copyright holders, (ii) preparation of derivative works or incorporation of the databases or contents thereof in any other work or system; (iii) downloading of the contents in their entirety or lengthy sequence. Authorized users are referred to the individual copyright holder and/or to the copyright holder's usage guidelines within this database for additional restrictions which may be imposed by the copyright holder.

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Field Guide Updated December 4, 2007

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