Tohutoro APA (7th ed.)

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

Tohutoru Kātū Chicago (17th ed.)

Kraus, Edward Henry, me Chester Baker Slawson. Gems and Gem Materials. 5a. ed. Nueva York: McGraw-Hill, 1947.

Tohutoro MLA (9th ed.)

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