Verma, Ram U. “The ϵ−Optimality Conditions for Multiple Objective Fractional Programming Problems for Generalized (ρ, η)−invexity of Higher Order”. CUBO, A Mathematical Journal 14, no. 2 (June 1, 2012): 01–13. Accessed May 18, 2024. https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1339.