LOWYCK, J.; WIELEMANS, W. IN MEMORIAM Prof. Em. Cyriel De Keyser 1921-2001. Pedagogische Studiën, [S. l.], v. 79, n. 1, 2002. Disponível em: https://pedagogischestudien.nl/article/view/14716.. Acesso em: 18 jul. 2025.