An overview of grey literature and how to find it.
What is grey literature?
According to the Oxford English Dictionary grey literature is "documentary material which is not commercially published or publicly available, such as technical reports or internal business documents." This includes technical and government reports, statistics, and social media outputs.
For a more detailed overview of grey literature and how to search for it, see the What is grey literature? guide by the University of Leeds Library.
Grey literature databases
Some library databases that contain grey literature.
More grey literature on the Internet
Lens.org is freely available and covers patents, scholarly works, and biological sequence analysis. You can include or exclude countries and regions, and see how the documents have been cited in other people’s research.