Paisan Sukjairungwattana และ Sasarux Petcherdchoo. (2007) A comparative study of adverbs. Chulalongkorn University:ม.ป.ท.Paisan Sukjairungwattana และ Sasarux Petcherdchoo. 2007. A comparative study of adverbs. ม.ป.ท.:Chulalongkorn University;Paisan Sukjairungwattana และ Sasarux Petcherdchoo. A comparative study of adverbs. ม.ป.ท.:Chulalongkorn University, 2007. Print.