[1] Lenstra J.K. and RinnooyKan A.H.G. "Complexity of vehicle routing and scheduling problem", Networks, vol. 11, pp. 221-227. 1981.
[2] Dantzig G.B. and Ramser J.M. "The truck dispatching problem, Management Science", vol. 6, pp. 81–91. 1959.
[3] FarzanehDaneshzand. "The Vehicle-Routing Problem", Logistics Operations and Management, pp. 127-153, 2011.
[4] Lin C, Choy KL, Ho GTS, Chung SH, Lam HY. "Survey of Green Vehicle Routing Problem: Past and future trends". Expert System Applications.vol 41, pp. 1118-1138. 2014.
[5] Privé, J., Renaud, J., Boctor, F., &Laporte, G. "Solving a vehicle-routing problem arising in soft-drink distribution". Journal of the Operational Research Society, vol. 57, pp. 1045–1052. 2006.
[6] Gribkovskaia, I., Laporte, G., &Shyshou, A. "The single vehicle routing problem with deliveries and selective pickups". Computers & Operations Research, vol. 35, pp. 2908–2924. 2008.
[7] Aras, N., Aksen, D., &Tekin, M. T. "Selective multi-depot vehicle routing problem with pricing". Transportation Research Part C: Emerging Technologies, vol. 19, pp. 866–884. 2011.
[8] Beltrami, E. J., &Bodin, L. D. "Networks and vehicle routing for municipal waste collection". Networks, vol. 4, pp. 65–94. 1974.
[9] Sculli, D., Mok, K. C., & Cheung, S. H. "Scheduling vehicles for refuse collection". Journal of the Operational Research Society, vol. 38, pp. 233–239. 1987.
[10] Mansini, R., &Speranza, M. G. "A linear programming model for the separate refuse collection service". Computers & Operations Research, vol. 25, pp. 659–673. 1998.
[11] Ramos, T., & Oliveira, R. "Delimitation of service areas in reverse logistics networks with multiple depots". Journal of the Operational Research Society, vol. 62, pp.1198–1210. 2011.
[12] Mar-Ortiz, J., Adenso-Diaz, B., & González-Velarde, J. "Design of a recovery network for WEEE collection: the case of Galicia", Spain. Journal of the Operational Research Society, vol. 62, pp. 1471–1484. 2011.
[13] Tania Rodrigues Pereira Ramos, Maria Isabel & Ana Paula Barbosa Povoa. "A multi- product, multi-depot periodic vehicle routing problem in a reverse logistics system". POMS 21st Annual conference. Vancouver, Canada. 2010.
[14] Schultmann, F., Zumkeller, M., &Rentz, O. "Modeling reverse logistic tasks within closed-loop supply chains: an example from the automotive industry". European Journal of Operational Research, vol. 171, pp. 1033–1050. 2006.
[15] le Blanc, I., van Krieken, M., Krikke, H., &Fleuren, H. "Vehicle routing concepts in the closed-loop container network of ARN – a case study". OR Spectrum, vol. 28, pp.53–71. 2006.
[16] Kim, H., Yang, J., & Lee, K. "Vehicle routing in reverse logistics for recycling end-of-life consumer electronic goods in South Korea". Transportation Research Part D: Transport and Environment, vol. 14, pp. 291–299. 2009.
[17] Kim, H., Yang, J., &Lee, K. "Reverse logistics using a multi-depot VRP approach for recycling end-of-life consumer electronic products in South Korea". International Journal of Sustainable Transportation, vol. 5, pp. 289–318. 2011.
[18] Dell’Amico, M., Righini, G., &Salani, M. "A branch-and-price approach to the vehicle routing problem with simultaneous distribution and collection". Transportation Science, vol. 40, pp. 235–247. 2006.
[19] Alshamrani, A., Mathur, K., &Ballou, R. H. "Reverse logistics: simultaneous design of delivery routes and returns strategies". Computers & Operations Research, vol. 34, pp. 595–619. 2007.
[20] Dethloff, J. "Vehicle routing and reverse logistics: the vehicle routing problem with simultaneous delivery and pick-up". OR Spectrum, vol. 23, pp. 79–96. 2001.
[21] Çatay, B. "A new saving-based ant algorithm for the vehicle routing problem with simultaneous pickup and delivery". Expert Systems with Application, vol. 37, pp. 6809–6817. 2010.
[22] Tasan, A. S., & Gen, M. "A genetic algorithm based approach to vehicle routing problem with simultaneous pick-up and deliveries". Computer & Industrial Engineering, vol. 62, pp. 755–761. 2012.
Sally Kassem&Mingyuan Chen. "Solving reverse logistics vehicle routing problems with time windows". Int J AdvManufTechnol, vol. 68, pp.57–68. 2013