Hawking, S. W., & Penrose, R. (1996). The nature of space and time. Princeton University Press, ; Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Hawking, S. W., agus Roger Penrose. The Nature of Space and Time. Princeton, N.J. : New York ; New Delhi: Princeton University Press, ; Oxford University Press, 1996.
Lua MLA (8ú heag.)Hawking, S. W., agus Roger Penrose. The Nature of Space and Time. Princeton University Press, ; Oxford University Press, 1996.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.