LAVRENYUK, S. P.; PROTSAKH, N. P. Variational Ultraparabolic Inequalities. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 12, p. 1616–1628, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3870. Acesso em: 5 dec. 2025.