DILDABEK, G.; TENGAYEVA, A.A. Existence of eigenvalues of problem with shift for an equation of parabolic-hyperbolic type. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 82, n. 2, p. 48–55, 2016. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/98. Acesso em: 24 aug. 2025.