Grey Liteature
Grey literature publications are non-conventional publications. They may include, but are not limited to the following types of materials: reports -- technical, statistical, or market research reports -- theses, conference proceedings,and official documents not published commercially.
OpenGrey is a portal to European grey literature. OpenGrey covers the fields of sciences, technology, biomedical sciences, and social sciences and humanities.
The New York Academy of Medicine's Grey Literature Report publishes state reports with electronic access from 1999-2016. It contains un-indexed materials that are not produced by commercial publishers.
MedNar searches across more than 60 medical research sources, including commercial databases, medical societies, NIH resources, and other government resources.
This registry and database provides regularly updated information about federally and privately supported clinical research from around the world.
The EU Clinical Trials Regsiter
The European Union Clinical Trials Register allows you to search trials conducted by European Union member states.