Most standards support searching additional sources after database searching is completed. Depending on the topic, one or all of the below methods may be appropriate. A librarian may be able to contribute to developing a plan.
The resources listed below detail types and access points for various types of grey literature. Including grey literature sources has been demonstrated to have an impact on findings in several studies.
These tools are useful for finding a variety of types of grey literature, as opposed to more specific resources listed in boxes below.