Cita APA (7th ed.)

Penrose, R. (2004). The road to reality: A complete guide to the laws of the universe (First American edition.). A.A. Knopf.

Cita Chicago (17th ed.)

Penrose, Roger. The Road to Reality: A Complete Guide to the Laws of the Universe. First American edition. New York: A.A. Knopf, 2004.

Cita MLA (8th ed.)

Penrose, Roger. The Road to Reality: A Complete Guide to the Laws of the Universe. First American edition. A.A. Knopf, 2004.

Atenció: Aquestes cites poden no estar 100% correctes.