JANSSEN, A. Integration seperat stetiger Funktionen. MATHEMATICA SCANDINAVICA, [S. l.], v. 48, p. 68–78, 1981. DOI: 10.7146/math.scand.a-11900. Disponível em: https://www.mscand.dk/article/view/11900. Acesso em: 6 may. 2024.