APA (7th ed.) Citation

Webster, R., & Anderson, B. W. (1983). Gems: Their sources, descriptions and indentification (4th ed.). Butterworths.

Chicago Style (17th ed.) Citation

Webster, Robert, and B. W. Anderson. Gems: Their Sources, Descriptions and Indentification. 4th ed. London: Butterworths, 1983.

MLA (9th ed.) Citation

Webster, Robert, and B. W. Anderson. Gems: Their Sources, Descriptions and Indentification. 4th ed. Butterworths, 1983.