Paithoon Thuamkorn และ Somsook Khongpun. (2009) Characteristics and teaching techniques of tutors in tutorial schools. Thammasat University:ม.ป.ท.Paithoon Thuamkorn และ Somsook Khongpun. 2009. Characteristics and teaching techniques of tutors in tutorial schools. ม.ป.ท.:Thammasat University;Paithoon Thuamkorn และ Somsook Khongpun. Characteristics and teaching techniques of tutors in tutorial schools. ม.ป.ท.:Thammasat University, 2009. Print.