Cita APA (7th ed.)

Unsworth, W. (1977). Encyclopedia of mountaineering ([Revised ed.].). Penguin.

Cita Chicago (17th ed.)

Unsworth, Walt. Encyclopedia of Mountaineering. [Revised ed.]. Harmondsworth ; New York: Penguin, 1977.

Cita MLA (8th ed.)

Unsworth, Walt. Encyclopedia of Mountaineering. [Revised ed.]. Penguin, 1977.