APA (7e ed.) Bronvermelding

Kraus, E. H., & Slawson, C. B. (1947). Gems and gem materials (5th ed.). McGraw-Hill.

Chicago (17e ed.) Bronvermelding

Kraus, Edward Henry, en Chester Baker Slawson. Gems and Gem Materials. 5th ed. New York: McGraw-Hill, 1947.

MLA (9e ed.) Bronvermelding

Kraus, Edward Henry, en Chester Baker Slawson. Gems and Gem Materials. 5th ed. McGraw-Hill, 1947.