VitrychenkoI. E. “On Stability of an<em class="a-Plus-plus">n</em&gt;Th-Order Equation in a Critical Case”. Ukrains’kyi Matematychnyi Zhurnal 47, no. 8 (August 25, 1995): 1138–1143. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5511.