BAGEMIHL, F. Congruous and incongruous one-to-one correspondences. MATHEMATICA SCANDINAVICA, [S. l.], v. 1, p. 256–260, 1953. DOI: 10.7146/math.scand.a-10383. Disponível em: https://www.mscand.dk/article/view/10383. Acesso em: 6 may. 2024.