LAVRENYUK, S. P.; OLISKEVYCH, M. O. Mixed problem for a semilinear ultraparabolic equation in an unbounded domain. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 59, n. 12, p. 1661–1673, 2007. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3420. Acesso em: 6 dec. 2025.