DAS, Koushik. Sufficiency and duality of set-valued fractional programming problems via second-order contingent epiderivative. Yugoslav Journal of Operations Research, [S. l.], v. 32, n. 2, p. 167–188, 2022. DOI: 10.2298/YJOR210218019D. Disponível em: https://yujor.erc.fon.bg.ac.rs/index.php/yujor/article/view/696. Acesso em: 3 nov. 2025.