SOËTARD, M. Friedrich Fröbel. Padres y Maestros / Journal of Parents and Teachers, [S. l.], n. 350, p. 45–48, 2013. Disponível em: https://revistas.comillas.edu/index.php/padresymaestros/article/view/1002. Acesso em: 19 abr. 2024.