四阶Duffing方程周期解的存在性
贾秀利,, 卢秀双, 冀书关
Existence of Periodic Solutions for Fourth Order Duffing Equations
JIA Xiuli,, LU Xiushuang, JI Shu guan
吉林大学学报(理学版) . 2007, (02): 219 -220 .