Indriati, Menik Yuni, et al. “Identifying and Eliminating Waste in a Coal Mining Industry: The Value Stream Mapping Analysis”. International Journal of Sustainable Construction Engineering and Technology, vol. 14, no. 5, Oct. 2023, pp. 290-04, https://publisher.uthm.edu.my/ojs/index.php/IJSCET/article/view/12146.