VILLALOBOS MURILLO, Johnny; BRENES CHAVARRÍA, Steven; MORA RIVERA, Sonia. Computer-aided tool for the teaching of relational algebra in data base courses. Uniciencia, [S. l.], v. 26, n. 1-2, p. 179–195, 2012. Disponível em: https://www.revistas.una.ac.cr/index.php/uniciencia/article/view/3873. Acesso em: 18 apr. 2026.