ALFSEN, Erik M. On a General Theory of Integration Based On Order. Mathematica Scandinavica, Berkeley, CA, United States, v. 6, p. 67–79, 1958. DOI: 10.7146/math.scand.a-10537. Disponível em: https://journals.msp.org/mscand/article/view/2808. Acesso em: 25 jul. 2026.