Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.