Literature that is NOT published in traditional sources such as books and journals is referred to as “Grey Literature”.
Conference proceedings and theses are the most common types of Grey Literature in the academic context, but examples also include technical and research reports, government publications, policy papers, annual reports, fact sheets, maps, geological surveys and statistics.
Google: A search of Google using keywords and the advanced search functionality allows for limiting searches to specific domains such as government or research web sites. This can be useful for tracking down grey literature.Policy Commons: Platform for think-tank publishing, grey literature, and government reports.
Grey Matters: a practical search tool for evidence-based medicine: Published by The Canadian Agency for Drugs and Technologies in Health (CADTH). Provides details on where to locate grey literature in Australia and other countries
OpenGrey: System for Information on Grey Literature in Europe, is your open access to 700.000 bibliographical references of grey literature (paper) produced in Europe and allows you to export records and locate the documents.
The Grey Literature Report: The report is a bimonthly publication of The New York Academy of Medicine Library alerting readers to new grey literature publications in health services research and selected public health topics.