Huynh, Diem. “Characterizations of Variational Convergence of Bifunctions Defined on Products of Two Sets”. VNUHCM Journal of Engineering and Technology 3, no. SI3 (December 31, 2020): SI141-SI149. Accessed April 7, 2026. https://et.vnuhcmjournal.com.vn/index.php/et/article/view/643.