Jinzhi Lei, Xiong Li, Ping Yan, Meirong Zhang. Twist Character of the Least Amplitude Periodic Solution of the Forced Pendulum. SIAM J. Math. Analysis, 35(4):844-867, 2003. [doi]
@article{LeiLYZ03,
title = {Twist Character of the Least Amplitude Periodic Solution of the Forced Pendulum},
author = {Jinzhi Lei and Xiong Li and Ping Yan and Meirong Zhang},
year = {2003},
doi = {10.1137/S003614100241037X},
url = {http://dx.doi.org/10.1137/S003614100241037X},
researchr = {https://researchr.org/publication/LeiLYZ03},
cites = {0},
citedby = {0},
journal = {SIAM J. Math. Analysis},
volume = {35},
number = {4},
pages = {844-867},
}