BAN, Đoàn V.; THẠNH, L. M.; HÙNG, H. B. The equivalent expression between the OODB query language OQL and the object algebra. Journal of Computer Science and Cybernetics, [S. l.], v. 20, n. 3, p. 257–269, 2012. DOI: 10.15625/1813-9663/20/3/1488. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/1488. Acesso em: 19 may. 2024.