Ngamwilai Somwangsombat และ Chakkaphan Sutthirat. (2009) Gemological Characteristics of Corundum from Gia Nghia, Southern Vietnam. <i>Bulletin of Earth Sciences of Thailand (BEST)</i>, <i>2</i>(2-Jan), 63-65.Ngamwilai Somwangsombat และ Chakkaphan Sutthirat. "Gemological Characteristics of Corundum from Gia Nghia, Southern Vietnam". Bulletin of Earth Sciences of Thailand (BEST) 2 (2009):63-65.Ngamwilai Somwangsombat และ Chakkaphan Sutthirat. Gemological Characteristics of Corundum from Gia Nghia, Southern Vietnam. Department of Geology, Chulalongkorn University:ม.ป.ท. 2009.