This section gives a basic overview of grey literature.
For in-depth grey lit search tips and resources, see our Comprehensive Searching Guide - Grey Literature.
Grey Literature is any literature that has not been published through traditional means. It is often excluded from large databases and other mainstream sources. Depending on your research topic, some information needed may only be available in grey lit.
Common sources of grey literature include:
If you're doing a a systematic review, leaving grey lit excludes a major section of the available research. To avoid bias and to ensure that the review is as thorough as possible, always search grey literature.
“Pages,” Alexandra*Rae 
Key Grey Lit Resources:
Additional Grey Literature Search Tips:
Appraising Grey Literature:
For more help finding Canadian, US, UK, UN, and international information, such as:
Check out one of these guides on government or policy information, or contact gov.info@utoronto.ca.
