@article{IVM_1967_8_a8,
     author = {A. G. Ugodchikov},
     title = {Differentiation of functions which realize an approximate conformal mapping},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {76--81},
     publisher = {mathdoc},
     number = {8},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1967_8_a8/}
}