1 "olored stones Blue Sapphire" Gemological Institute of America 5-6, 2002
2 "emstone enhancement and detection in the 1990s?" 36 : 336-, 2000
3 "em Reference Guide" Gemological Institute of America 74-, 1995
4 "The color enhancement of natural Zambian amethyst by the hydrothermal treatment?" 14 : 75-, 2004
5 "Growth of composite sapphire/Ti sapphire by the hydrothermal method?" 277 : 200-, 2005
6 "?tandard catalog of Gem Values?" Geoscience Press Inc 151-152, 1944
7 "?olor encyclopedia of Gemstones?" 71-74, 1987
8 "?he sapphire mines of Kashmir? Himalayan Journal 13" 73-, 1946
1 "olored stones Blue Sapphire" Gemological Institute of America 5-6, 2002
2 "emstone enhancement and detection in the 1990s?" 36 : 336-, 2000
3 "em Reference Guide" Gemological Institute of America 74-, 1995
4 "The color enhancement of natural Zambian amethyst by the hydrothermal treatment?" 14 : 75-, 2004
5 "Growth of composite sapphire/Ti sapphire by the hydrothermal method?" 277 : 200-, 2005
6 "?tandard catalog of Gem Values?" Geoscience Press Inc 151-152, 1944
7 "?olor encyclopedia of Gemstones?" 71-74, 1987
8 "?he sapphire mines of Kashmir? Himalayan Journal 13" 73-, 1946