APA (7th ed.) Citation

Webster, R., & Anderson, B. W. (1983). Gems, their sources, descriptions, and identification (4th ed.). Butterworths.

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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