PACHPATTE, B. G. Inequalities applicable to retarded Volterra integral equations. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 4, p. 285–292, 2004. DOI: 10.5556/j.tkjm.35.2004.186. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/186. Acesso em: 18 aug. 2022.