NG, K.-C. SELF-FOCUSING AND SELF-TRAPPING OF SPHERCIAL BEAMS IN A NONLINEAR MEDIUM. Tamkang Journal of Mathematics, [S. l.], v. 25, n. 2, p. 179–187, 1994. DOI: 10.5556/j.tkjm.25.1994.4441. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4441. Acesso em: 4 may. 2024.