Koestler, A., & Butterfield, H. (1964). The Sleepwalkers: A history of man's changing vision of the universe; with an introduction by Herbert Butterfield. Penguin.
Dyfyniad Arddull ChicagoKoestler, Arthur, and Herbert Butterfield. The Sleepwalkers: A History of Man's Changing Vision of the Universe; with an Introduction by Herbert Butterfield. London: Penguin, 1964.
Dyfyniad MLAKoestler, Arthur, and Herbert Butterfield. The Sleepwalkers: A History of Man's Changing Vision of the Universe; with an Introduction by Herbert Butterfield. Penguin, 1964.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.