Berczyński, Paweł, and Yury Kravtsov. “Gaussian Beam Evolution in Nonlinear Media of Kerr Type”. Photonics Letters of Poland 5, no. 1 (March 28, 2013): pp. 29–31. Accessed March 28, 2024. https://photonics.pl/PLP/index.php/letters/article/view/5-11.