Phornphan Thongbanchachai และ Sasarux Petcherdchoo. (2006) Pedagogical grammar of Mandarin Chinese negation "Bu" and "Mei (You)" for Thai unversity students. Chulalongkorn University:ม.ป.ท.Phornphan Thongbanchachai และ Sasarux Petcherdchoo. 2006. Pedagogical grammar of Mandarin Chinese negation "Bu" and "Mei (You)" for Thai unversity students. ม.ป.ท.:Chulalongkorn University;Phornphan Thongbanchachai และ Sasarux Petcherdchoo. Pedagogical grammar of Mandarin Chinese negation "Bu" and "Mei (You)" for Thai unversity students. ม.ป.ท.:Chulalongkorn University, 2006. Print.