@article{10_4153_CMB_1990_015_3,
     author = {Li, Chengzhi and Rousseau, Christiane and Wang, Xian},
     title = {A {Simple} {Proof} for the {Unicity} of the {Limit} {Cycle} in the {Bogdanov-Takens} {System}},
     journal = {Canadian mathematical bulletin},
     pages = {84--92},
     year = {1990},
     volume = {33},
     number = {1},
     doi = {10.4153/CMB-1990-015-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1990-015-3/}
}