Wakul Theerawongsakorn และ Jintana Thunwaniwat. (2006) Pedagogical grammar of the aspect "ZHE" in Mandarin Chinese for Thai university students. Chulalongkorn University:ม.ป.ท.Wakul Theerawongsakorn และ Jintana Thunwaniwat. 2006. Pedagogical grammar of the aspect "ZHE" in Mandarin Chinese for Thai university students. ม.ป.ท.:Chulalongkorn University;Wakul Theerawongsakorn และ Jintana Thunwaniwat. Pedagogical grammar of the aspect "ZHE" in Mandarin Chinese for Thai university students. ม.ป.ท.:Chulalongkorn University, 2006. Print.