AKTAŞ, M. F. Lyapunov-type inequalities for two classes of nonlinear systems with homogeneous Dirichlet boundary conditions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 70, n. 6, p. 727–738, 2018. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1591. Acesso em: 5 dec. 2025.