"A central, open-access repository of research by members of the Harvard community."
OpenGey - System for Information on Grey Literature in Europe
"System for Information on Grey Literature in Europe, is your open access to 700.000 bibliographical references of grey literature (paper) produced in Europe and allows you to export records and locate the documents. Examples of grey (gray) literature include technical or research reports, doctoral dissertations, some conference papers, some official publications, and other types of grey literature. OpenGrey covers Science, Technology, Biomedical Science, Economics, Social Science and Humanities. The site includes preprints from the GL conferences (GreyNet International) in full text."