Malampong K, Sripathomswat K. An Application of Whale Optimization Algorithm for Heterogeneous Vehicle Routing Problem with Soft Time Windows. TJOR [internet]. 2023 Jun. 19 [cited 2025 Apr. 15];11(1):32-43. available from: https://ph02.tci-thaijo.org/index.php/TJOR/article/view/248569