Bazaly В. V., and A. F. Tedeev. “On the Estimates of the Rate of Stabilization for Some Problems With Free Boundary ”. Ukrains’kyi Matematychnyi Zhurnal, vol. 44, no. 10, Oct. 1992, pp. 1299-06, https://umj.imath.kiev.ua/index.php/umj/article/view/8224.