Wagimin, W., E. Kusrini, J. Ali, and V. Noor Helia. “The Effect of Leadership on Employee Performance With Total Quality Management (TQM) As a Mediating Variable in Indonesian Petroleum Companies: A Case Study”. International Journal of Integrated Engineering, Vol. 11, no. 5, Sept. 2019, pp. 180-8, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/4217.