@article{IM2_1990_35_2_a8,
     author = {S. I. Pinchuk and Sh. I. Tsyganov},
     title = {The smoothness of $\operatorname{CR}$-mappings between strictly pseudoconvex hypersurfaces},
     journal = {Izvestiya. Mathematics},
     pages = {457--467},
     year = {1990},
     volume = {35},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1990_35_2_a8/}
}