Cita APA (7a ed.)

Heinlein, R. A. (1990). Citizen of the galaxy (13. print.). Ballantine Books.

Cita Chicago Style (17a ed.)

Heinlein, Robert Anson. Citizen of the Galaxy. 13. print. New York: Ballantine Books, 1990.

Cita MLA (9a ed.)

Heinlein, Robert Anson. Citizen of the Galaxy. 13. print. Ballantine Books, 1990.