APA (7th ed.) Citation

Hurlbut, C. S., & Kammerling, R. C. (1991). Gemology (2. ed.). Wiley.

Chicago Style (17th ed.) Citation

Hurlbut, Cornelius Searle, and Robert C. Kammerling. Gemology. 2. ed. New York u.a: Wiley, 1991.

MLA (9th ed.) Citation

Hurlbut, Cornelius Searle, and Robert C. Kammerling. Gemology. 2. ed. Wiley, 1991.