APA Edition Citation

Boegel, H., & John, S. Collector's guide to minerals and gemstones.

Chicago Edition Citation

Boegel, Hellmuth, and Sinkankas John. Collector's Guide to Minerals and Gemstones.

MLA Edition Citation

Boegel, Hellmuth, and Sinkankas John. Collector's Guide to Minerals and Gemstones.

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