APA (7th ed.) Citation

Baum, L. F. (1990). The wonderful wizard of Oz. Project Gutenberg.

Chicago Style (17th ed.) Citation

Baum, L. Frank. The Wonderful Wizard of Oz. Champaign, Ill: Project Gutenberg, 1990.

MLA (9th ed.) Citation

Baum, L. Frank. The Wonderful Wizard of Oz. Project Gutenberg, 1990.