USA and Canada

• Proquest Digital Dissertations

Great Britain and Ireland

• Index to Theses

France

• ABES: SUDOC-Catalogue
• Le Fichier central des thèses (theses in preparation)
  
• Print sources for French Dissertations

Italy

• Tesionline (This is a site where individuals can register and publish the online version of theses. All levels from bachelor's to doctoral degrees. Not comprehensive coverage. See also the OPAC's of the Italian national libraries and the catalogs of "tesi di dottorato" of universities.)