Grey literature is defined as "information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing" ie. where publishing is not the primary activity of the producing body." — ICGL Luxembourg definition, 1997. Expanded in New York, 2004

Types of Grey Literature

• Government Information
• Dissertations and Theses
• Conference Proceedings (select Conference Proceedings Citation Index)
• Newspapers and Magazines
• Think Tanks

Resources

• Alternative Press Index - Indexes over 300 periodicals, newspapers and magazines which report and analyze the practices and theories of cultural, economic, political, and social change.  90% of the publications indexed in API are unique.
• Canadian Research Index (Provides detailed citations to monographs and serial publications in the Microlog microfiche collection)
• GreySource - directory of organizations
• Grey Matters (a checklist for health technology assessment from the Canadian Agency for Drugs and Technologies in Health (CADTH))
• Grey Literature Report (searchable bimonthly publication of The New York Academy of Medicine (NYAM))
• How-to Guide
• Finding the Hard to Finds: Searching for Grey Literature - University of British Columbia