APA (7th ed.) Citation

Hurlbut, C. S., & Switzer, G. S. (1979). Gemology. Wiley.

Chicago Style (17th ed.) Citation

Hurlbut, Cornelius S., and George S. Switzer. Gemology. New York: Wiley, 1979.

MLA (9th ed.) Citation

Hurlbut, Cornelius S., and George S. Switzer. Gemology. Wiley, 1979.