VitrychenkoI. E. (2004). 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(2), 264-270. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3750