Mustaffa, Nur Kamaliah. “Alternative Configuration in Earthmoving Operations for Minimizing Unit Emissions and Unit Cost”. International Journal of Integrated Engineering 12, no. 1 (February 17, 2020): 297–303. Accessed June 29, 2022. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/5730.