Surachai Sombatboriboon และ Yupaporn Kemprasit. (1987) Invertible matrices over semirings. Chulalongkorn University:ม.ป.ท.Surachai Sombatboriboon และ Yupaporn Kemprasit. 1987. Invertible matrices over semirings. ม.ป.ท.:Chulalongkorn University;Surachai Sombatboriboon และ Yupaporn Kemprasit. Invertible matrices over semirings. ม.ป.ท.:Chulalongkorn University, 1987. Print.