THI, Vũ Đức. Some observations on the relation schemes in the relational datamodel. <b>Journal of Computer Science and Cybernetics</b>, <i>[S. l.]</i>, v. 17, n. 2, p. 51–55, 2012. DOI: 10.15625/1813-9663/17/2/2444. Disponível em: https://jcc.vast.vn/jcc/article/view/2444. Acesso em: 5 nov. 2025.