ProQuest is a company that sells online subscriptions to libraries for access to research materials. Users with a connection to an academic library can obtain documents online.
The UMI microfilm vault was founded in 1938 and is now one of ProQuest Information and Learning's assets. It is the largest commercially available microform collection in the world. Its 5.5 billion page images deliver 500 years of information, drawn from thousands of literary, journalistic, and scholarly works. Every year it adds another 37 million images of contemporary information. It has 1.9 million PhD dissertations and other theses online, with abstracts, 24 page summaries, and full texts. They can be read online free (through subscribing libraries) or purchased by anyone in paper format.