@article{ZNSL_1999_262_a9,
     author = {E. L. Patsevich},
     title = {Some estimates for the derivative of a quasiconformal reflection},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {199--203},
     year = {1999},
     volume = {262},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1999_262_a9/}
}