Das, Koushik, and Chandal Nahak. “Set-Valued Optimization Problems via Second-Order Contingent Epiderivative”. Yugoslav Journal of Operations Research 31, no. 1 (February 1, 2021): 75–94. Accessed August 25, 2025. https://yujor.erc.fon.bg.ac.rs/index.php/yujor/article/view/648.