ระดมสุขส., พันธุ์ไทยบ., ขัตติยาสุวรรณศ. and ภิญโญอนันตพงษ์บ. (2019) “the Factors Influencing the “Thinking” (‘khit pen’) of Undergraduates at Institutions of Higher Education in the Lower Northeastern Region: thinking khit pen”, Ph.D. in Social Sciences Journal, 9(1), pp. 76-87. Available at: https://so05.tci-thaijo.org/index.php/phdssj/article/view/108531 (Accessed: 30March2020).