YERMACHENKO, Inara; SADYRBAEV, Felix. On a problem for a system of two the second order differential equations via the theory of vector fields. Nonlinear Analysis: Modelling and Control, [S. l.], v. 20, n. 2, p. 175–189, 2015. DOI: 10.15388/NA.2015.2.2. Disponível em: https://www.journals.vu.lt/nonlinear-analysis/article/view/13532. Acesso em: 11 apr. 2025.