Não informado. (1934). Gems & Gemology. Gemological Institute of America.
Chicago Style (17th ed.) CitationNão informado. Gems & Gemology. Santa Monica, Calif: Gemological Institute of America, 1934.
MLA (8th ed.) CitationNão informado. Gems & Gemology. Gemological Institute of America, 1934.
Warning: These citations may not always be 100% accurate.