Asimov, I. (1989). Frontiers: New discoveries about man and his planet, outer space, and the universe. Plume.
Chicago-Zitierstil (17. Ausg.)Asimov, Isaac. Frontiers: New Discoveries About Man and His Planet, Outer Space, and the Universe. New York: Plume, 1989.
MLA-Zitierstil (9. Ausg.)Asimov, Isaac. Frontiers: New Discoveries About Man and His Planet, Outer Space, and the Universe. Plume, 1989.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.