LÂN, L. T. Hexagrams by the mathematical graph of congruence. Journal of Computer Science and Cybernetics, [S. l.], v. 19, n. 2, p. 110–116, 2012. DOI: 10.15625/1813-9663/19/2/1502. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/1502. Acesso em: 1 jul. 2024.