|Mildred Wirt Benson is one of several authors who has written mystery novels about girl detective Nancy Drew under the pseudonym Carolyn Keene. Benson, however, was the first of them, and wrote 23 of the 30 books in the original series. An agreement with the publishing company forced Benson to keep her identity secret; the truth about her work was revealed years later when she testified in a court case involving the publisher of the books. The series has sold over 200 million books and has been translated into 17 languages, but Benson was paid only $125 per book and received no royalties. In addition to the Nancy Drew books, Benson wrote the Penny Parker mystery series and several short stories; she also worked as a journalist for the Toledo Times (later known as The Blade). In 1927 Benson became the first person to receive a master's degree in journalism from the University of Iowa.