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Evidence Synthesis

Gray Literature

Gray Literature is the "wealth of knowledge and information produced by organizations, governments and industry, covering a wide range of subject areas and professional fields, not controlled by commercial publishing." (Pisa Declaration 2014)

  • includes:
    • hard to find studies, reports, or dissertations
    • conference abstracts or papers
    • governmental or private sector research
    • clinical trials - ongoing or unpublished
    • experts and researchers in the field   

When conducting a systematic review it is important to include literature that has not formally been published in sources as it helps to prevent publication bias. Searching grey literature is supported/mandated by the Cochrane Collaboration, the Campbell Collaboration, JBI and the National Academy of Medicine (U.S.).

How do I find Gray Literature?

  • Search the Gray Literature Gateways listed in the next tab.
  • Search the corporation, institution, or agency that is most likely to produce the type of information you are looking for.
  • For online searches include terms to target grey literature such as: report, "think tank", "white paper", policy, statistics.
  • Search Free Databases.
  • Search library catalogs at large scientific institutions or Worldcat.
  • Search Google Scholar to target academic research.
  • Consult with a SciTech librarian.
https://www.nyam.org/library/collections-and-resources/grey-literature-report/The DOAJ (Directory of Open Access Journals) was launched in 2003 with 300 open access journals. Today, this independent database contains over 15 000 peer-reviewed open access journals covering all areas of science, technology, medicine, social sciences, arts and humanities. Open access journals from all countries and in all languages are welcome to apply for inclusio
The report is a publication produced by the The New York Academy of Medicine between 1999 - 2016, alerting readers to new grey literature publications in health services research and selected urban health topics. As of January 2017, the Grey Literature Report website and database will be discontinued and will no longer be updated, but the resources will still be accessible. Grey Literature resources are cataloged and indexed using MeSH. The database allows full text keyword searching as well as subject searching and serves as an archive for the Reports.
  • GreyNet InternationalThe goal of GreyNet is to facilitate dialog, research, and communication between persons and organisations in the field of grey literature. GreyNet further seeks to identify and distribute information on and about grey literature in networked environments. Its main activities include the International Conference Series on Grey Literature, the creation and maintenance of web-based resources, a moderated Listserv and combined Distribution List, The Grey Journal (TGJ), and curriculum development. 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. HP Labs, one of the pre-eminent industrial research laboratories in the world, is passionate about making our research real - driving technology to commercialization in the areas most important to our customers and society.
  • iDAI.objects arachne
  • NTIS - central resource for government-funded scientific, technical, engineering, and business related information.
  • Open Grey - system for information on grey literature in Europe. Open access to 700,000 references to the grey literature.
  • PLOS One
  • PubChemPubChem is an open chemistry database at the National Institutes of Health (NIH). “Open” means that you can put your scientific data in PubChem and that others may use it. Since the launch in 2004, PubChem has become a key chemical information resource for scientists, students, and the general public.
  • Science.govScience.gov is a gateway to U.S. government science information. The portal offers free access to research and development (R&D) results and scientific and technical information from scientific organizations across 13 federal agencies. Science.gov makes it possible for users to search over 60 databases, over 2,200 websites, and over 200 million pages of authoritative federal science information in many formats, including full-text documents, citations, scientific data supporting federally funded research, and multimedia.
  • ScienceOpen.comScienceOpen is a discovery platform with interactive features for scholars to enhance their research in the open, make an impact, and receive credit for it. We provide context building services for publishers, to bring researchers closer to the content than ever before. Our advanced search and discovery functions, combined with post-publication peer review, recommendation, social sharing, and collection-building features make ScienceOpen the only research platform you’ll ever need.
  • Springer Link
  • World Health Organization - providing leadership on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring and assessing health trends.
  • New York Academy of Medicine Grey Literature Report  - a bimonthly publication of The New York Academy of Medicine (NYAM) alerting readers to new gray literature publications in health services research and selected public health topics. NOTE: Discontinued as of Jan 2017, but resources are still accessible.
  • Gray Source Index
  • NAL - National Agricultural Library AGRICOLA
  • Nature Precedings
  • The OAIster Database
  • OpenDOAR - directory of academic repositories
  • Clinical Trials

Gray Lit and Regional Database Syntax

Search strategies for gray literature and regional databases often have to be distilled significantly from the main search strategy. This is due to the fact that many grey literature and regional databases cannot handle complex search strategies and special syntax. In addition, searching grey literature and regional databases with all the terms from the main search strategy sometimes returns far too many results to screen. The recommended method of simplifying a search strategy is to combine a few of the most important terms from each key concept of your research question. See an example below.

Research Question: What is the effectiveness of Vitamin B12 supplements in reducing morbidity in pregnant women with HIV infection?

  • Key Concept 1 distilled terms: B12, B 12, cobalamin
  • Key Concept 2 distilled terms: pregnancy/pregnant, gestate/gestation/gestational
  • Key Concept 3 distilled terms: ​HIV, human immunodeficiency virus

Distilled Search Strategy: (B12 OR "B 12" OR cobalamin) AND (pregnan* OR gestat*) AND (HIV OR "human immunodeficiency virus")

Evidence Synthesis Institute: Grey Literature

From UMN Librariaies Time 3:10 minutes

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