Berezovsky, A. A., Mitropolskiy, Y. A., & Shkhanukov-Lafishev, M. K. (1996). Space-time localization in problems with free boundaries for a nonlinear second-order equation. Ukrains’kyi Matematychnyi Zhurnal, 48(2), 202-211. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/5348