What is 'grey literature'?
Materials that have not been published commercially and are not available via major databases are considered to be grey literature. This information may not have been published formally at all, and may not be peer reviewed. Grey literature includes reports, conference papers, clinical guidelines, registered trials, theses and dissertations, informal communication, websites, official documents, newsletters, and patents.
Some databases that contain conference papers include:
Repositories contain research outputs, which are considered grey literature. These resources can be unpublished, or could have been published in other forms. Repositories are a great place to find research findings before they are made available through a commercial publisher. Repositories can contain journal articles, book chapters, conference papes, creative works, data, or dissertations and theses.