The world's most comprehensive collection of dissertations and theses. Includes 2.7 million searchable citations to dissertation and theses from around the world from 1861 to the present day together with 1.2 million full text dissertations that are available for download in PDF format. Over 2.1 million titles are available for purchase as printed copies. The database offers full text for most of the dissertations added since 1997 and strong retrospective full text coverage for older works.