Active from 1926, American screenwriter Florence Ryerson was employed by Paramount Pictures when talkies came in. During this period, Ryerson's assignments included the studio's Fu Manchu films and the 1929 Philo Vance mystery The Canary Murder Case. It was another Philo Vance yarn, The Casino Murder Case, which brought her to MGM in 1935. Four years later, she was one of the credited screenwriters for the studio's musical classic The Wizard of Oz (1939). Thereafter, any screen derivation of Oz was obliged to carry Florence Ryerson's name in the credits, even the 1971 European quickie Aysecik and the Bewitched Dwarves in Dreamland (1971).