Boutet de Monvel, A., & Marchenko, V. (1997). The Cauchy problem for nonlinear Schrodinger equation with bounded initial data. Математическая физика, анализ, геометрия, 4(1-2), 3–45. вилучено із https://mag.ilt.kharkiv.ua/index.php/mag/article/view/m04-0003e