Systematic Reviews (Undergrad): Grey Literature

This guide will help you understand how to conduct a modified systematic review of research (no meta-analysis).

Grey literature

Grey literature is material that is not commercially published, and can be difficult to find.  It can come in the form of conference proceedings, technical reports, working papers, preprints, as well as blogs or podcasts.

Search or browse organizational websites (such as WHO, NIH, Robert Wood Johnson Foundation, etc.). Organizations produce reports, statistics, and other unpublished resources. Search sites individually and/or browse areas such as "publications" or "statistics."

Clinical Trial Registers

Trial registers provide information on both ongoing and completed trials.  Many registers include trial results for completed research, often before they are available through traditional, published sources and in many cases, they provide results for studies which are never published.

Conference Proceedings

Conference proceedings can be a great source of current research, and you may choose to include them in a systematic or scoping review if there is enough information for your analysis. Some databases, such as PsycInfo and Web of Science, include poster and presentation abstracts from conferences. Institutional repositories are also good sources and can be searched through Google Scholar.


Preprints are preliminary reports of work that have not been certified by peer review.

  • Last Updated: May 21, 2024 8:50 AM
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