Kolomiets, T., PogoruiA. О., and R. M. Rodriguez-Dagnino. “The First Passage Time and Estimation of the Number of Level-Crossings for a Telegraph Process”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 67, no. 7, July 2015, pp. 882-9, https://umj.imath.kiev.ua/index.php/umj/article/view/2031.