VitrychenkoI. E. “Critical Cases of the π-Stability of a Nonautonomous Quasilinear Equation of the <em class="a-Plus-plus">n</em&gt;Th Order”. Ukrains’kyi Matematychnyi Zhurnal 56, no. 2 (February 25, 2004): 264-270. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3750.