Le, Ngoc-Kien, Van-Nghi Tran, and Van-Hao Nguyen. 2026. “Some Applications of Directional Subdifferentials at Infinity to Vector Optimization Problems”. HPU2 Journal of Science: Natural Sciences and Technology 5 (01):76-86. https://doi.org/10.56764/hpu2.jos.2026.5.01.76-86.