APA (7th ed.) Citation

Hurlbut, C. S., & Kammerling, R. C. (1993). Gemología (2a ed.). Omega.

Chicago Style (17th ed.) Citation

Hurlbut, Cornelius Searle, and Robert C. Kammerling. Gemología. 2a ed. Barcelona: Omega, 1993.

MLA (9th ed.) Citation

Hurlbut, Cornelius Searle, and Robert C. Kammerling. Gemología. 2a ed. Omega, 1993.

Warning: These citations may not always be 100% accurate.