Pajaree Nipaspong และ Sumalee Chinokul. (2007) The effects of types of corrective feedback on students’ oral pragmatic competence on the use of refusals. Chulalongkorn University:ม.ป.ท.Pajaree Nipaspong และ Sumalee Chinokul. 2007. The effects of types of corrective feedback on students’ oral pragmatic competence on the use of refusals. ม.ป.ท.:Chulalongkorn University;Pajaree Nipaspong และ Sumalee Chinokul. The effects of types of corrective feedback on students’ oral pragmatic competence on the use of refusals. ม.ป.ท.:Chulalongkorn University, 2007. Print.