@article{Hongying Zhu:936, author = {Hongying Zhu,Minzhi Wei,Sumin Yang,Caoqing Jiang}, title = {Bifurcation of Limit Cycles from a Liénard System of Degree 4}, publisher = {Acta mathematica scientia,Series A}, year = {2021}, journal = {Acta mathematica scientia, Series A}, volume = {41}, number = {4}, eid = {936}, numpages = {17}, pages = {936}, keywords = {;LiĆ©nard system;Chebyshev system;Melnikov functions;Weak Hilbert's 16th problem}, url = {http://121.43.60.238/sxwlxbA/EN/abstract/article_16439.shtml}, doi = {} }