Bazaly В.V., Skrypnik , I.V. and Tedeev , A.F. (1992) “Conferences on nonlinear problems of mathematical physics and problems with free boundaries”, Ukrains’kyi Matematychnyi Zhurnal, 44(2), pp. 295–297. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/7846 (Accessed: 17 February 2026).