Khattara, A., Cherif-Khettaf, W. R. and Mostefai, M. (2019) “RETRACTED: An Efficient Metaheuristic Approach for the Multi-Period Technician Routing and Scheduling Problem”, Engineering, Technology & Applied Science Research. Greece, 9(5), pp. 4718–4723. doi: 10.48084/etasr.3091.