@article{10_4153_CMB_2004_041_4,
     author = {Pengcheng, Niu and Yanwu, Han and Junqiang, Han},
     title = {A {Hopf} {Type} {Lemma} and a $\text{CR}$ {Type} {Inversion} for the {Generalized} {Greiner} {Operator}},
     journal = {Canadian mathematical bulletin},
     pages = {417--430},
     year = {2004},
     volume = {47},
     number = {3},
     doi = {10.4153/CMB-2004-041-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2004-041-4/}
}