Deep, S., B. M. Salleh, and H. Othman. “Exploring the Role of Problem-Based Learning in Developing Conflict Resolving and Other Soft Skills - A Quasi-Experimental Study”. International Review of Management and Marketing, vol. 6, no. 4, Oct. 2016, pp. 738-4, https://econjournals.com/index.php/irmm/article/view/2890.