7. 刘斌,庾建设, 具时滞n维 Liénard型方程调和解的存在性, 数学物理学报3(2002), 323-331
5. Bing Liu and Jianshe Yu, Boundary value problem for a generalized Lienard equation, Appl. Math. J. Chinese Univ.Ser.B.1(2002),31-38