Howard, D., & Mabley, E. (1993). The tools of screenwriting: A writer's guide to the craft and elements of a screenplay. St. Martin's Press.

Howard, David, and Edward Mabley. The Tools of Screenwriting: A Writer's Guide to the Craft and Elements of a Screenplay. New York: St. Martin's Press, 1993.

Howard, David, and Edward Mabley. The Tools of Screenwriting: A Writer's Guide to the Craft and Elements of a Screenplay. St. Martin's Press, 1993.