Yodwangjai, S. and Malampong, K. (2023) “Hybrid Coronavirus Herd Immunity Optimizer with Whale Optimization Algorithm for Vehicle Routing Problem with Soft Time Windows”, Engineering and Technology Horizons , 40(1), pp. 98–114. available at: https://ph01.tci-thaijo.org/index.php/lej/article/view/250386 (accessed: 13 September 2026).