KallelN. and TimoumiМ. (2003) “Subharmonics of a Nonconvex Noncoercive Hamiltonian System”, Ukrains’kyi Matematychnyi Zhurnal, 55(11), pp. 1459-1466. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4016 (Accessed: 27July2024).