SverdanM. L., Tsar’kovE. F., and YasinskyV. K. “Asymptotic Behavior of Solutions of Pulse Systems With Small Parameter and Markov Switchings. I. Uniform Boundedness of Solutions”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 48, no. 10, Oct. 1996, pp. 1375-8, https://umj.imath.kiev.ua/index.php/umj/article/view/5223.