Rahman MS. A perturbation technique to compute initial amplitude and phase for the Krylov-Bogoliubov-Mitropolskii method. Tamkang J. Math. [Internet]. 2012 Dec. 31 [cited 2024 Apr. 26];43(4):563-75. Available from: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/853