HE, Pengfei, and Jing LI. “Vehicle Routing Problem With Partly Simultane-Ous Pickup and Delivery for the Cluster of Small and Medium Enterprises”. Archives of Transport 45, no. 1 (March 31, 2018): 35–42. Accessed January 2, 2026. https://archivesoftransport.com/index.php/aot/article/view/419.