You can find information in our Evaluating sources guide.
Grey literature:
- may be more current than peer reviewed papers due to the time it takes for the peer review process and publication
- provides access to new ideas and perspectives
- may contain more detail and be written in a more accessible style than a scientific paper
- may perform a broad exploration of a topic and current conversations around research and ideas
It is important to consider including grey literature in your search strategy when undertaking a systematic review. Including grey literature can help ensure you are capturing all the relevant information on your topic, as well as helping to eliminate publication bias by searching beyond literature databases. Searching for grey literature is highly recommended by the National Academy of Medicine (NAM; formerly Institute of Medicine, IoM) and under the Cochrane and JBI guidelines.
Schöpfel, J. and Farace, D.J., 2018. 'Grey Literature', in McDonald, J.D. and Levine-Clark, M. (eds.), Encyclopedia of library and information sciences.
Saleh, A. A., Ratajeski, M. A. and Bertolet, M., 2014. 'Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized'. Evidence based library and information practice, vol. 9, no. 3, pp.28–50. https://doi.org/10.18438/b8dw3k