KALITA , E. A. Properties of solutions of half-linear elliptical systems of nondivirgent kind. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 2, p. 184–191, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7831. Acesso em: 7 apr. 2025.