APA (7th ed.) Citation

Heller, D., & Heller, D. (1962). The Berlin wall. Walker.

Chicago Style (17th ed.) Citation

Heller, Deane, and David Heller. The Berlin Wall. New York: Walker, 1962.

MLA (9th ed.) Citation

Heller, Deane, and David Heller. The Berlin Wall. Walker, 1962.