Er’omenko, V. O. and Aliluiko, A. M. (2010) “Quasiperiodic solutions of degenerate linear systems of second-order ordinary differential equations”, Ukrains’kyi Matematychnyi Zhurnal, 62(6), pp. 773–783. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2908 (Accessed: 5May2024).