PFEFFER, W. F. An Integral in Topological Spaces II. MATHEMATICA SCANDINAVICA, [S. l.], v. 27, p. 77–104, 1970. DOI: 10.7146/math.scand.a-10989. Disponível em: https://www.mscand.dk/article/view/10989. Acesso em: 4 may. 2024.