RONNOW, U. Remarks on Compact Mappings. MATHEMATICA SCANDINAVICA, [S. l.], v. 10, p. 217–220, 1962. DOI: 10.7146/math.scand.a-10529. Disponível em: https://www.mscand.dk/article/view/10529. Acesso em: 5 may. 2024.