TƯỜNG, N. B. The key and normal forms in relation scheme. Journal of Computer Science and Cybernetics, [S. l.], v. 16, n. 4, p. 30–33, 2013. DOI: 10.15625/1813-9663/16/4/2920. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/2920. Acesso em: 24 nov. 2024.