APA (7th ed.) Citation

Keller, P. C. (1990). Gemstones and Their Origins. Springer US.

Chicago Style (17th ed.) Citation

Keller, Peter C. Gemstones and Their Origins. Boston, MA: Springer US, 1990.

MLA (9th ed.) Citation

Keller, Peter C. Gemstones and Their Origins. Springer US, 1990.

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