KLEE, V. L. J. The structure of semispaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 4, p. 54–64, 1956. DOI: 10.7146/math.scand.a-10455. Disponível em: https://www.mscand.dk/article/view/10455. Acesso em: 5 may. 2024.