Rattanamanee, T., S. Nanthavanij, and A. Dumrongsiri. “HEURISTIC PROCEDURE FOR MULTI-WORKDAY VEHICLE ROUTING PROBLEM WITH PRE-ASSIGNED WORKERS AND MANUAL UNLOADING”. International Journal of Industrial Engineering: Theory, Applications and Practice, vol. 27, no. 3, Dec. 2020, doi:10.23055/ijietap.2020.27.3.6207.