VitrychenkoI. E. (2000) “On the functional polystability of certain essentially nonlinear nonautonomous differential systems”, Ukrains’kyi Matematychnyi Zhurnal, 52(2), pp. 197-207. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4408 (Accessed: 22November2024).