Kravchuk, K. G., and A. K. Vidybida. “Delayed Feedback Makes Neuronal Firing Statistics Non-Markovian”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 64, no. 12, Dec. 2012, pp. 1587-09, https://umj.imath.kiev.ua/index.php/umj/article/view/2685.