SamоіlenkоA. M. (1966) “The numerical-analytical method of investigating periodic systems of ordinary differential equations. II”, Ukrains’kyi Matematychnyi Zhurnal, 18(2), pp. 50-59. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8716 (Accessed: 24November2024).