Sze, San Nah, Siaw Ying Doreen Sek, Jeeu Fong Sze, Wai Shiang Cheah, and Kang Leng Chiew. “Vehicle Routing Problem With Simultaneous Pickup and Delivery”. International Journal on Advanced Science, Engineering and Information Technology 10, no. 4 (August 6, 2020): 1360–1366. Accessed July 22, 2024. https://ijaseit.insightsociety.org/index.php/ijaseit/article/view/10234.