中国科学院数学与系统科学研究院期刊网
Infinitely Many Periodic Solutions for a Class of Second-order Hamiltonian Systems
Ming-hai YANG, Yue-fen CHEN, Yan-fang XUE
Acta Mathematicae Applicatae Sinica(English Series) . 2016, (1): 231 -238 .  DOI: 10.1007/s10255-016-0552-2