MATTSON, D. A. Dense $p$-Subspaces of Proximity Spaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 27, p. 223–226, 1970. DOI: 10.7146/math.scand.a-11000. Disponível em: https://www.mscand.dk/article/view/11000. Acesso em: 8 may. 2024.