Muhammad Javed Khan, and Hamza Zafar. “An Extended TOPSIS Method for the Multiple Attribute Decision Making Problems Based on Double Hierarchy Linguistic Soft Sets (DHLSSs)”. VFAST Transactions on Mathematics 13, no. 2 (December 31, 2025): 41–54. Accessed May 13, 2026. https://vfast.org/journals/index.php/VTM/article/view/2161.