APA (7th ed.) Citation

Unsworth, W. (1975). Encyclopedia of mountaineering. Hale (u.a.).

Chicago Style (17th ed.) Citation

Unsworth, Walt. Encyclopedia of Mountaineering. London (u.a.): Hale (u.a.), 1975.

MLA (9th ed.) Citation

Unsworth, Walt. Encyclopedia of Mountaineering. Hale (u.a.), 1975.