NguyenManh Hung, and TranThi Loan. 2003. “On the Asymptotic Behavior of Solutions of the First Initial Boundary-Value Problems for Parabolic Equations”. Ukrains’kyi Matematychnyi Zhurnal 55 (8), 1143-52. https://umj.imath.kiev.ua/index.php/umj/article/view/3988.