APA-referens

Penrose, R., & Roger Penrose; foreword by Martin Gardner. (1991). The: Concerning computers, minds, and the laws of physics. New York, N.Y: Penguin Books.

Chicago-stil citat

Penrose, Roger, och Roger Penrose; foreword by Martin Gardner. The: Concerning Computers, Minds, and the Laws of Physics. New York, N.Y: Penguin Books, 1991.

MLA-referens

Penrose, Roger, och Roger Penrose; foreword by Martin Gardner. The: Concerning Computers, Minds, and the Laws of Physics. New York, N.Y: Penguin Books, 1991.

Varning: dessa hänvisningar är inte alltid fullständigt riktiga.