GRIPENBERG, G. Unique solutions of some Voltera integral equations. MATHEMATICA SCANDINAVICA, [S. l.], v. 48, p. 59–67, 1981. DOI: 10.7146/math.scand.a-11899. Disponível em: https://www.mscand.dk/article/view/11899. Acesso em: 18 may. 2024.