NGHĨA, V. Đức. Some rerults about choice functions. Journal of Computer Science and Cybernetics, [S. l.], v. 17, n. 1, p. 35–39, 2012. DOI: 10.15625/1813-9663/17/1/2427. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/2427. Acesso em: 2 may. 2024.