El-Sherbeny, Nasser Abdel-Magied. “Minimum Convex and Differentiable Cost Flow Problem With Time Windows”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 20, no. 1 (January 28, 2015): 139–150. Accessed May 20, 2024. https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/3368.