Cita APA (7th ed.)

Asimov, I. (1986). Foundation and earth. Doubleday & Co., Inc.

Cita Chicago (17th ed.)

Asimov, Isaac. Foundation and Earth. Garden City, N.Y: Doubleday & Co., Inc, 1986.

Cita MLA (9th ed.)

Asimov, Isaac. Foundation and Earth. Doubleday & Co., Inc, 1986.