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Systematic Reviews

A guide to conducting systematic reviews at the University of the Sunshine Coast

What is Grey Literature?

Grey literature is “information produced  by all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing”. (GreyNet)

Grey literature includes:

Theses and dissertations, conference proceedings, newsletters, reports, government documents, informal communications, translations, census data, research reports, technical reports, standards, patents, videos, clinical trials and practice guidelines, eprints, preprints, wiki articles, emails, blogs, listserv archives, repository content.

Grey literature may present a number of challenges for the researcher:

  • Difficult to find
  • Many documents are not web published
  • Older documents may not be archived
  • Short print runs may lead to lack of availability
  • Format and citation information may be inconsistent
  • Volume of material may be over-whelming and consuming
  • Quality of evidence varies.

Clinical Trials Registers

  • Cochrane Central Register of Clinical Trials (CENTRAL) - Details of published articles taken from bibliographic databases (notably MEDLINE and EMBASE), and other published and unpublished sources. In addition, each Cochrane Review Group maintains and updates a collection of controlled trials relevant to its own area of interest.
  • ANZCTR (Australian New Zealand Clinical Trials Registry) - The ANZCTR is a Primary Registry in the World Health Organisation (WHO) Registry Network. It accepts trials for registration from all countries and from the full spectrum of therapeutic areas including trials of pharmaceuticals, surgical procedures, preventive measures, lifestyle, devices, treatment and rehabilitation strategies and complementary therapies.
  • Clinical  - Registry of federally and privately supported clinical trials conducted in the United States and around the world. Includes details about a trial's purpose, who may participate, locations, and phone numbers for more details.
  • Current Controlled Trials - Current Controlled Trials allows users to search, register and share information about randomised controlled trials. Access to all the information on this site is free; charges for the registration services offered by Current Controlled.
  • CenterWatch  - More than 875 clinical research centers and 600 companies offering a variety of services to the clinical trials community are profiled right here on! Locate research centers by medical expertise or geographic region and industry providers by type of services provided. Both profiles offer detailed information about the services they provide.
  • NCIC Clinical Trials Group  - the NCIC Clinical Trials Group is a cooperative oncology group which carries out clinical trials in cancer therapy, supportive care and prevention across Canada and internationally.
  • MRC Clinical Trials Unit - MRC Clinical Trials Unit runs trials in a range of disease areas.  We specialise in trials in HIV/AIDS and cancer, but we also run trials in other areas, for example arthritis and tuberculosis.
  • NIHR Clinical Research Network
  • WHO International Clinical Trials Registry Platform - Provides access to a central database containing the trial registration data sets provided by the registries from Australia, UK, USA, Japan, Korea, Brazil, China, Iran, Sri Lanka, Netherlands, Germany, Cuba, India. It also provides links to the full original records.
  • Cancer Trials - From Cancer Research UK
  • National Cancer Institute Clinical Trials - Search NCI's list of 10,000+ clinical trials now accepting participants.
  • IFMA Clinical Trials Portal - Links to IFPMA member company websites as well as other commercial and government-sponsored websites containing information on clinical trials provided by pharmaceutical companies.

Check also the lists included in Cochrane Handbook for Systematic Reviews of Interventions (2008, p. 114-117)


The Theses link on UniSC Library's guides provides details for how to find  Australian and international electronic and print theses.

Databases indexing Grey Literature

Source What is included?
Australian Policy Online Australian public policy reports and articles from academic research centres, think tanks, government and non-government organisations. Also features opinion and commentary pieces, video, audio and web resources focused on the policy issues facing Australia. A partnership of ANU's Australian National Institute for Public Policy and Swinburne's Institute for Social Research
Google Scholar
Articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites.


One-stop search across medical societies, NIH resources, other U.S. government websites, and patents.


Catalog of millions of records representing open access resources from open access collections worldwide. OAIster includes more than 25 million records representing digital resources from more than 1,100 contributors.


Directory of academic open access repositories. Search for the full-text of material held in open access repositories listed in the Directory using 'Search Repository Contents', or use OpenDOAR to find repositories or groups of repositories that fit particular needs using our 'Find' facility.


A component of the PsycNET site. Grey literature database relating to psychology, behavioural sciences, and health. Full-text is available for the majority of records (approximately 70% and growing), in addition to a complete abstract record.

Coverage consists primarily of material written for professionals but disseminated outside of peer-reviewed journals. Gateway to over 50 million pages of authoritative selected science information provided by U.S. government agencies, including research and development results Global science gateway-accelerating scientific discovery and progress through a multilateral partnership to enable federated searching of national and international scientific databases.

Conference Presentations

Source What is included? How to search
BIOMED CENTRAL MEETINGS Includes meeting abstracts published in BioMed Central Journals, usually includes abstracts and conference name. Browse list of journals indexing conferences.
MEDLINE Includes some citations to individual poster/paper abstracts – may include abstracts. Journal supplements often not included.

Limit search by "Publication Type" to:

  • Clinical conference
  • Congresses

or MESH heading "Congresses as topic"

SCOPUS Over 500 conference proceedings, 4.6 million conference papers from proceedings and journals

Limit search by "Document Type" to:

  • Conference paper
  • Conference review

Includes Conference Proceedings Citation Index - Science, and Conference and Proceedings Citation Index - Social Science and Humanities. Rarely includes abstract.

Limit search by "Document Type" to:

  • Meeting abstract
  • Proceedings paper

Web Searching

Google Scholar provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites. Google Scholar helps you find relevant work across the world of scholarly research.

BASE is one of the world's most voluminous search engines especially for academic web resources. BASE provides more than 240 million documents from more than 8,000 content providers. You can access the full texts of about 60% of the indexed documents for free (Open Access). BASE is operated by Bielefeld University Library (Germany).

Mednar is a free, publicly available deep web search engine that uses advanced federated search technology to return high quality results by submitting your search query - in real-time - to other well respected search engines. Mednar then collates, ranks and drops duplicates of the results.

Use Advanced Search to specify where to search (societies, government websites, etc).

OpenMD is another large free search engine similar to MedNar.

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