ProQuest Dissertations & Theses (PQDT) Global This link opens in a new windowPreviously known as Digital Dissertations, this database is the definitive guide to more than 2 million master's theses and doctoral dissertations. ProQuest Dissertations & Theses can be used to identify more than ninety percent of the doctoral dissertations accepted each year in North America. The database also covers thousands of dissertations and theses from around the globe. Each dissertation published since July 1980 includes a 350-word abstract written by the author. Master's theses published since 1988 include 150-word abstracts. Bibliographic citations are available for dissertations dating back to 1861, and 24-page previews are available for thousands of the more recent dissertations available in the database.