Tshering, K., and T. Sawangmek. “THE RELATIONSHIP BETWEEN PRINCIPAL’S INSTRUCTIONAL LEADERSHIP AND SCHOOL EFFECTIVENESS IN THE URBAN SCHOOLS OF BHUTAN”. Journal of Education and Innovation, vol. 18, no. 3, Sept. 2016, pp. 226-3, https://so06.tci-thaijo.org/index.php/edujournal_nu/article/view/66611.