MENDOZA, Marvin R.; CABEZAS, Carlos. Emerging manifestations of variational thinking in students initial calculation. Portal de la Ciencia, [S. l.], v. 13, p. 45–65, 2018. DOI: 10.5377/pc.v13i0.5967. Disponível em: https://www.camjol.info/index.php/PC/article/view/5967. Acesso em: 4 apr. 2026.