Broer HW. A Global Kam-Theorem: Monodromy in Near-Integrable Perturbations of Spherical Pendulum. J. Math. Fund. Sci. [Internet]. 2019Jan.17 [cited 2025Oct.24];34(2&3):309-24. Available from: https://journals.itb.ac.id/index.php/jmfs/article/view/9268