Thitiworatumrong, P. “Relationship between trait and behavioral leaderships and Organizational commitment of the sales staffs: A case study of a big company as the Finance service business (Loan and Credit Card) located”. Human Resource and Organization Development Journal, vol. 9, no. 1, June 2017, pp. 60-79, https://so01.tci-thaijo.org/index.php/HRODJ/article/view/138401.