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Evidence Synthesis, Systematic Review Services : Select Gray Literature Sources

The Importance of Searching the Gray/Grey Literature

Searching the gray literature as part of your review process is an important step toward countering publication bias. For instance, relying solely upon what is easily discovered or readily available through commercial publishing platforms, or is published only in English, or that only reports on a study's significant findings may miss critical research outputs and voices.

Defining Gray/Grey Literature

Gray literature is the research (materials and data) produced by individuals and organizations who may communicate this output through non-commercial publishing channels including reports of various types (annual, project, research, technical), working papers, white papers, theses and dissertations, preprints, and conference meeting proceedings. These individuals and organizations may be affiliated with academic institutions and/or conduct their research as staff or partners with the following: 

  • Government Agencies
  • Agricultural Experiment/Research Stations
  • Extension Services
  • Intergovernmental and Non-governmental organizations (NGOs) 
  • Professional, membership organizations and societies
  • Businesses

This page provides links to a few library-licensed and freely-available resources. It is by no means an exhaustive list. While some resources to the gray literature will have powerful search engines for constructing and running a search and a means by which to export records, many will not and may necessitate browsing files or running simple site searches. 

Finding Aids by Subject and Type:

Agriculture, Environment, Life Sciences

Education, Social Sciences

Engineering

Medicine, Nursing, Public Health

Multidisciplinary

Business & Industry Reports

Library Catalogs & Institutional Repositories