GUDKOV, V. V. A family of the spiral solutions of the nonlinear Klein‐Gordon equation. Mathematical Modelling and Analysis, [S. l.], v. 3, n. 1, p. 98–103, 1998. DOI: 10.3846/13926292.1998.9637092. Disponível em: https://journals.vilniustech.lt/index.php/MMA/article/view/9993. Acesso em: 2 jun. 2025.