THI, V. Đức. Some observations on the relation schemes in the relational datamodel. Journal of Computer Science and Cybernetics, [S. l.], v. 17, n. 2, p. 51–55, 2012. DOI: 10.15625/1813-9663/17/2/2444. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/2444. Acesso em: 1 may. 2024.