Vlasenko, L. A., and A. M. Samoilenko. 2009. “Optimal Control With Impulsive Component for Systems Described by Implicit Parabolic Operator Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 61 (8), 1053-65. https://umj.imath.kiev.ua/index.php/umj/article/view/3080.