Grey literature is comprised of materials produced by organizations instead of commercial publishers. Grey literature consists of documents produced by government, academic, business or organizations "where publishing is not the primary activity of the producing body" (Greynet). Documents include reports, white papers, working papers, plans, policy, etc.
Grey literature does not always undergo a peer review process and the quality of the grey literature can vary widely, so be sure to evaluate the authority of the source you plan to use. If you need to review evaluating sources, we have a guide for your reference.
Grey literature can be found in several ways. Organizations that produce grey literature typically list it on their web pages under sections titled "Reports," "Documents," "Library," "Publications," etc. Some organizations, such as professional organizations, may produce grey literature that is only available to organization members. Sites themselves can be searched using Google using the site: command. For example:
site:library.ubc.ca transportation engineering
Examples you can find here include annual reports, conference proceedings, technical reports, theses, white papers, and even informal communication such as blogs, emails, or social media posts.