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Searching systematically: ACQUIRE - Selecting your sources

How to search systematically, from developing a good research question to managing your search results

Which resources

Your choice of database or information resource will depend on:

Time available, what resources you have access to, the type of information you require, what you need the information for, your area of expertise.

However, it is expected that more than one database is searched. Usually, you would search Medline (Ebsco/OVID), PubMed and Embase as the minimum. Depending on your topic or area of interest, other databases would be expected to be searched.

Which resources

Information is published in a variety of sources including:

  • Journals
  • Books
  • Grey literature (Conference proceedings, Government publications,   Reports, Theses & dissertations)
  • Internet (Google Scholar,
  • Databases (Medline, Cinhal, PscyInfo, ERIC, Web of Science, etc.)


Remember! Resources can consist of different types of information:

  • Clinical guidelines : NCEC (Ireland),(NICE (UK), NGC (US), etc.
  • Systematic reviews : Cochrane Library, Campbell Collabboration, etc.
  • Qualitative research
  • Clinical Trials : Clinical,, etc.

Some sources such as PubMed, Embase, Web of Science will provide access to a wide range of information types

While others such as Cochrane Database of Systematic Reviews, Trials registers, NICE (UK) provide access to a specific type of information.

How to search Medline/Cinahl

Grey literature

"Grey literature is usually understood to mean literature that is not formally published in sources such as books or journal articles" (Lefebvre et al. 2011, section

Health research

Duke University Medical Center Library & Archives, Grey Literature

Dissertations and Theses

Science, Technology, Humanities 

Hand Searching

Hand searching is searching through medical journals or conference abstract proceedings for reports of research which are not indexed in the major electronic databases like MEDLINE and Embase. It can also involve searching forward reference and screening the bibliography of selected studies.

How to search Pubmed

National Health Library & Knowledge Service. Health Service Executive. Dr. Steevens' Hospital, Dublin 8. Tel: 01-6352555/8. Email: