Kalia, Weiz Shahzad, Dewanto Harjunowibowo, and Lenny. 2018. “Sales People Training Programme Scheduling Using Multiple Objective Linear Programming: Case Study of an Indonesian Motorcycle Distributor”. Journal of Mobile Multimedia 14 (1):75-94. https://journals.riverpublishers.com/index.php/JMM/article/view/4433.