KapustyanV. E. “The Asymptotics of Constrained Control in Optimal Singular Parabolic Problems”. Ukrains’kyi Matematychnyi Zhurnal 45, no. 10 (October 25, 1993): 1345–1355. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5939.