Hawking, S., & Penrose, R. (1996). The nature of space and time. Princeton, N.J.: Princeton University Press.
Παραπομπή Chicago StyleHawking, Stephen, and Roger Penrose. The Nature of Space and Time. Princeton, N.J.: Princeton University Press, 1996.
Παραπομπή MLAHawking, Stephen, and Roger Penrose. The Nature of Space and Time. Princeton, N.J.: Princeton University Press, 1996.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.