BoichukО. A., ZhuravlyovV. Р., and PokutnyiО. О. “Bounded Solutions of Evolutionary Equations”. Ukrains’kyi Matematychnyi Zhurnal 70, no. 1 (January 25, 2018): 7-28. Accessed December 5, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/1539.