BerezovskyA. A., MitropolskiyYu. A., and Shkhanukov-LafishevM. Kh. “Space-Time Localization in Problems With Free Boundaries for a Nonlinear Second-Order Equation”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 2 (February 25, 1996): 202-211. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5348.