Penrose, R. (2004). The road to reality: A complete guide to the laws of the universe (First American edition.). A.A. Knopf.
Lua i Stíl Chicago (17ú heag.)Penrose, Roger. The Road to Reality: A Complete Guide to the Laws of the Universe. First American edition. New York: A.A. Knopf, 2004.
Lua MLA (8ú heag.)Penrose, Roger. The Road to Reality: A Complete Guide to the Laws of the Universe. First American edition. A.A. Knopf, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.