ISBELL, J. R. Atomless Parts of Spaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 31, p. 5–32, 1972. DOI: 10.7146/math.scand.a-11409. Disponível em: https://www.mscand.dk/article/view/11409. Acesso em: 27 may. 2022.