@article{IM_1993__111_1_144081,
     author = {Linda Preiss Rothschild and M.S. Bouendi},
     title = {A generalized complex {Hopf} {Lemma} and its applications to {CR} mappings.},
     journal = {Inventiones mathematicae},
     pages = {331--348},
     publisher = {mathdoc},
     volume = {111},
     number = {1},
     year = {1993},
     zbl = {0781.32021},
     url = {http://geodesic.mathdoc.fr/item/IM_1993__111_1_144081/}
}