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Sources of information

Page history last edited by Pierre PLUYE 8 years, 2 months ago

Several sources of information and combinations of sources can be used (personal files, experts' files, research networks, specialized journals, existing reviews, reference books, bibliographic databases, and citation tracking among others).

Thus, carefully define the scope of sources of information in accordance to your financial, time and human resources.

The scope of sources must be comprehensive in systematic mixed studies reviews, which allows an exhaustive search of relevant documents.


This section is structured in three main parts: 1) Bibliographic databases, 2) Other approaches to finding studies, 3) Searching the grey literature.  


1) Bibliographic Databases 


Several bibliographic databases are available on the web.  These databases can include references of different types of documents such as journal articles, conference proceedings, reports and books.  The choice of databases depends on several criteria such as the subject areas, access, date coverage, controlled vocabulary, and type of documents. A librarian must be consulted for searches in multiple databases since each database has its own operators. 


The following table presents some bibliographic databases.  




Allied & Complementary Medicine (AMED)

AMED is a database produced by the Health Care Information Service of the British Library. It covers a selection of journals on complementary medicine, palliative care, and several professions allied to medicine.

Cumulative Index to Nursing & Allied Health Literature (CINAHL)

CINAHL database covers journals from nursing, allied health, biomedicine, alternative/ complementary medicine, consumer health, and health sciences librarianship.

Current Contents

Current contents covers a very wide selection of subsets in which two might be of relevance in health: Social & Behavioral Sciences and Clinical Medicine. Also, it covers not only journal articles but also reviews, meeting abstracts, and editorials.

Evidence-Based Medicine (EBM) reviews

  • ACP Journal Club
  • Cochrane Central Register of Controlled Trials  (CCTR)
  • Cochrane Database of Systematic Reviews (CDSR)
  • Cochrane Methodology of Reviews of Effects (CMR)
  • Database of Abstracts of Reviews of Effects (DARE)
  • Health Technology Assessment (HTA)
  • NHS Economic Evaluation Database (NHSEED)

Evidence-based medicine reviews include several databases from the Cochrane Collaboration. The databases include controlled trials (CCTR) and systematic reviews (CDSR and DARE). Also, the ACP Journal Club, published by the American College of Physicians, aims to select, summarise and comment articles that warrant immediate attention by physicians. Since 2008, three new databases were added in the collection on economics (NHSEED), health technology assessment (HTA), and methodological research (CMR). 

Education Resource Information Center (ERIC)

ERIC provides access to bibliographic records of journal articles, books, research syntheses, conference papers, technical reports, policy paper, and other education-related materials. ERIC is sponsored by the U.S. Department of Education, Institute of Education Sciences (IES).

Excerpta Medica (EMBASE)

EMBASE covers similar topic to MEDLINE and includes biomedical and pharmaceutical international journals. Several covered fields could be relevant for this review such as clinical and experimental human medicine, health policy and management, public health, occupational health, and environmental health. Also, there is selective coverage for nursing, medicine, psychology, and alternative medicine.


HealthSTAR comprises data from the database MEDLINE and focuses of both clinical and non-clinical aspects of health care delivery. This database not only contains citations and abstracts to journal articles but also monographs, technical reports, meeting abstracts and papers, book chapters, government documents, and newspaper articles.


MEDLINE is the United States National Library of Medicine's (NLM) database that provides information from several fields such as medicine, nursing, allied health and pre-clinical sciences.

ProQuest Dissertations and Theses

ProQuest Dissertations and Theses database provides full-text theses and dissertations published by graduate students from over 1000 academic institutions worldwide. This database is multidisciplinary.


PsycINFO is a database of psychological literature and related disciplines including medicine, psychiatry, nursing, sociology, education, pharmacology, physiology, and linguistics. This database provides citations and abstracts to journal articles and books.


Scopus is a multidisciplinary database for citation tracking.  It covers the literature on sciences, applied sciences, health sciences, social sciences, arts and human sciences. It provides 100% Medline coverage. It contains abstract and citation for academic journal articles.

Sociological Abstracts

Sociological abstracts database covers an international literature in sociology and related disciplines in the social and behavioural sciences. The database provides abstracts of journal articles, abstracts of books, book chapters, dissertations, and conference papers.


2) Other Approaches to Finding Studies 


Searching the literature is an iterative process. In order to cover the literature on one specific question, other approaches than bibliographic searches can be used.  For example, searching primary bibliographic databases may be (must be if systematic review) complemented by a citation tracking using the database SCOPUS for instance. Citation tracking can be reiterated up to saturation (i.e., until no new relevant publication found). 


The following table presents some common approaches: 





Social networks are powerful sources of information. Experts can be contacted through personal contacts, mailing lists and forums.

Journal Hand Searches


Provide a list of journal titles in alphabetical order using full titles. State the earliest year searched, together with the latest year searched, and any missing journal issues which were not searched. 

Dissertations and Theses

Provide a list of databases searched and range of years for each, as well as the terms searched. Indicate any limits such as doctoral theses only. 

Clinical Trial Registries


Indicate the name and URL of any registries searched, range of years, as well as terms searched. 

Conference Proceedings


Indicate the full title of the conference, and include the title of the proceedings as well if it exists, or the journal information if it was published as part of a journal. 

Citation Tracking*


Indicate if reference lists of obtained articles were consulted for locating earlier studies.

Unpublished Studies


Provide a brief summary including databases, or other grey literature sources searched. Include here efforts to contact investigators for information about unpublished studies. 


*Citation tracking is a useful method to identify references that are very likely to be relevant to your topic. Citation searching involves looking at the references at the end of a relevant article as well as at who has cited the article in question (“Cited by”). By looking at who has cited the article, also allows you to assess how your research topic has progressed.  If the article has not been cited, some databases allow you to set up alerts. Some databases will allow you to use a related records/related articles/related documents function (any article that shares at least one citation in common with your article).   Tools for citation tracking are Google Scholar, and citation databases such as ISI Web of Science or Scopus.       


3) Systematically Searching the Grey Literature


“Grey Literature is a field in library and Information science that deals with the production, distribution, and access to multiple document types produced on all levels of government, academics, business, and organization in electronic and print formats not controlled by commercial publishing i.e., where publishing is not the primary activity of the producing body.” [About GreyNet. (2012). Grey Literature Network Service. Retrieved 13:21, June 17, 2013 from http://www.greynet.org/greynethome/aboutgreynet.html.]


Examples: Theses, conference proceedings, white papers, reports, government documents, bibliographies, newsletters, lectures, blogs, informal communication, website information, and audiovisual materials.



  • Potential to fill knowledge gaps left by mainstream scholarship and research
  • Searchable and accessible on the internet for free


Where to look for it

  • Specialized databases and portals
  • Google and Google Scholar
  • Reference lists and bibliographies (to identify citations that are not indexed)
  • Experts in the field


Best practices

  • Test and document in detail your search strategy
  • Ask a librarian and peers to review your strategy and recommend additional sources
  • Identify key organizations relevant to your topic, search their publications and/or contact their documentation specialist


Additional information



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