SugieJ. and YamaokaN. (2006) “Multilayer structures of second-order linear differential equations of Euler type and their application to nonlinear oscillations”, Ukrains’kyi Matematychnyi Zhurnal, 58(12), pp. 1704–1714. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3566 (Accessed: 22November2024).