Koestler, A., & Butterfield, H. (1964). The Sleepwalkers: A history of man's changing vision of the universe; with an introduction by Herbert Butterfield. Penguin.
Citazione stile Chigago Style (17a edizione)Koestler, Arthur, e Herbert Butterfield. The Sleepwalkers: A History of Man's Changing Vision of the Universe; with an Introduction by Herbert Butterfield. London: Penguin, 1964.
Citatione MLA (9a ed.)Koestler, Arthur, e Herbert Butterfield. The Sleepwalkers: A History of Man's Changing Vision of the Universe; with an Introduction by Herbert Butterfield. Penguin, 1964.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.