Slyusarchuk, V. Yu. “Linear Differential-Functional Equations With Absolutely Unstable Solutions”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 11 (November 25, 2019): 1570-1578. Accessed September 26, 2022. http://umj.imath.kiev.ua/index.php/umj/article/view/1536.