ProQuest is an excellent tool for accessing information from periodicals, newspapers, out-of-print books, dissertations, and scholarly collections in various formats. The archive includes more than 5 millions pages.
Pro Quest Information and Learning is a big company which manages agreements with 9,000 publishers in the world to give access to their records. The website provides historical and current newspaper databases, offering full-text and full-image articles in pdf format
Records are provided in a wide range of formats: full-text, cd-rom, microfilms, pdf, images. Most records are accompanied by comments, metainfos and bibliographic data
Pro Quest provides access to a large quantity of periodicals, newspapers, dissertations, articles and other kinds of records. It's the only offsite repository of digital information for the Library of Congress
Politics and History, Social Sciences and Government represent important areas on the website, including access to public records and archives
Updating rate varies according to the nature of the records. Most of them are updated daily