Finding Grey Literature: Home

Grey (or gray) literature refers to materials produced by organizations that are not formally published through traditional academic or commercial channels. These materials may include research, reports, datasets, and policy documents created to support an organization's operations or goals. While such documents may never undergo formal publication, they can still provide valuable, often unique insights for your research.

Since grey literature is typically not peer-reviewed, it is essential to critically evaluate the information it contains and cross-reference it with other reliable sources. However, grey literature can be considered reliable and be referenced in your publications if it comes from a credible source.

Grey literature encompasses a wide range of document types that are not typically published through conventional channels. Common forms of grey literature include:

• Theses and Dissertations
• Preprint Articles
• Government Reports
• Conference Proceedings
• Technical Papers
• Clinical Trials
• Datasets
• White Papers

Beyond these general categories, the most useful types of resources for your project will depend on your specific topic. Tailoring your search to include relevant grey literature can uncover valuable information and data that might not be available through traditional scholarly publications.

Broader View of Available Research

Searching grey literature alongside published scholarship can offer a more comprehensive understanding of the research available on a topic. Valuable data and studies produced by various organizations may not undergo the formal publication process, yet they can significantly contribute to the body of knowledge.

Timely Access to Recent Developments

Grey literature often captures the latest developments in a field of study. The formal publication process can be lengthy, sometimes taking years for an article or book to become available. In contrast, grey literature resources, such as preprint articles, are accessible for review immediately.

Mitigate Null Result Publication Bias

Reviewing grey literature can offer a less biased perspective on recent research compared to relying solely on popular databases. Studies with significant results are often favored for publication, leaving many studies with little or no change excluded from scholarly literature. Despite being overlooked for publication, these studies can provide a valuable foundation for future research. You can read more about null result publication bias here.

Highly Recommended for Systematic Reviews

If you are working on a systematic review, it is highly recommended to include a survey of grey literature. This is essential for gaining a comprehensive understanding of the available research. Additionally, the widely consulted Cochrane and JBI handbooks for systematic reviews emphasize the importance of searching grey literature and consider it a high priority. You can find more information on grey literature and systematic reviews here.