Ulrich’s Periodicals Directory™ is a bibliographic database providing detailed, comprehensive, and authoritative information on serials published throughout the world. It covers all subjects, and includes publications that are published regularly or irregularly and are circulated free of charge or by paid subscription. Ulrich’s was first published in 1932. It was known initially as "Periodicals Directory: A Classified Guide to a Selected List of Current Periodicals Foreign and Domestic." This title continued through the third edition published in 1938. Then, with the 4th edition (1943), the title became Ulrich’s Periodicals Directory: A Selected Guide to Current Periodicals, Inter-American Edition (with a focus on non-European titles because of the difficulty in getting information during WWII). From 1943-1965, the title was Ulrich’s Periodicals Directory. Then, with the 11th edition in 1965, it became known as Ulrich’s International Periodicals Directory, the title it held until the publication of the 39th edition in 2000, when it reverted to an earlier title, Ulrich’s Periodicals Directory. It also incorporated Irregular Serials and Annuals in 1988. Whatever the name or the scope, Ulrich’s remains the global source for periodicals information since 1932.