Cita APA (7a ed.)

Hawking, S., & Penrose, R. (1996). The nature of space and time. Princeton University Press.

Cita Chicago Style (17a ed.)

Hawking, Stephen, y R. Penrose. The Nature of Space and Time. Princeton: Princeton University Press, 1996.

Cita MLA (9a ed.)

Hawking, Stephen, y R. Penrose. The Nature of Space and Time. Princeton University Press, 1996.