Cita APA (7a ed.)

Asimov, I. (1979). Opus 200. Houghton Mifflin Company.

Cita Chicago Style (17a ed.)

Asimov, Isaac. Opus 200. Boston: Houghton Mifflin Company, 1979.

Cita MLA (9a ed.)

Asimov, Isaac. Opus 200. Houghton Mifflin Company, 1979.