Natnael Mekonenn and Balasundaram 2018. Optimization of Vehicle Routing in Simultaneous Pickup and Delivery Service: A Case study. International Journal of Advances in Scientific Research and Engineering (IJASRE), ISSN:2454-8006, DOI: 10.31695/IJASRE. 4, 12 (Dec. 2018), 72–80. DOI:https://doi.org/10.31695/IJASRE.2018.33007.