LAVRENT'EV, A. S.; MISHURA, Yu. S. The Hille-Yosida theorem for resolvent operators of multiparameter semigroups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 48, n. 1, p. 57–65, 1996. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5363. Acesso em: 14 apr. 2025.