GreySource Index - Public Gateway to Grey Literature

"The GreySource Index provides examples of grey literature to the average net-user and in so doing profiles organizations responsible for its production, processing, open access, and distribution. Only web-based resources that explicitly refer to the term grey literature (or its equivalent in any language) are listed. GreySource identifies the hyperlink directly embedded in a resource, thus allowing immediate and virtual exposure to grey literature in multiple subject based disciplines...."