[Gray literature] is commonly defined as any documentary material that is not commercially published and is typically composed of technial reports, working papers, and conference proceedings. The greatest challenges . . . are the process of identificaltion, . . . . Added to this is the absence of editorial control, raising questions about authenticity and reliability. Yet despite these considerations, gray literature is continually referenced in scholarly articles and dissertations and therefore remains an issue [in scholarly communication].

Included in this [page] are Web sites that aid in understanding the nature of gray literature as well as various search tools. The focus is upon freely available resources that offer some full-text coverage. . . .