OLUBUMMO, A. Finitely Additive Measures on the Non-Negative Integers. MATHEMATICA SCANDINAVICA, [S. l.], v. 24, p. 186–194, 1969. DOI: 10.7146/math.scand.a-10929. Disponível em: https://www.mscand.dk/article/view/10929. Acesso em: 3 may. 2024.