Cita APA (7th ed.)

Asimov, I. (1989). Frontiers: New discoveries about man and his planet, outer space, and the universe. Plume.

Cita Chicago (17th ed.)

Asimov, Isaac. Frontiers: New Discoveries About Man and His Planet, Outer Space, and the Universe. New York: Plume, 1989.

Cita MLA (9th ed.)

Asimov, Isaac. Frontiers: New Discoveries About Man and His Planet, Outer Space, and the Universe. Plume, 1989.