Storozh, O. G., and O. B. Shuvar. 2004. “Conditions for the Maximal Dissipativity of Almost Bounded Perturbations of Smooth Restrictions of Operators Adjoint to Symmetric Ones”. Ukrains’kyi Matematychnyi Zhurnal 56 (7), 966–976. https://umj.imath.kiev.ua/index.php/umj/article/view/3813.