APA (7th ed.) Citation

Lenzen, G., & Lapworth, P. B. (1983). Diamonds and diamond grading (1st Eng. ed.). Butterworths.

Chicago Style (17th ed.) Citation

Lenzen, G., and Patricia B. Lapworth. Diamonds and Diamond Grading. 1st Eng. ed. London ; Boston: Butterworths, 1983.

MLA (9th ed.) Citation

Lenzen, G., and Patricia B. Lapworth. Diamonds and Diamond Grading. 1st Eng. ed. Butterworths, 1983.