@article{UZKU_1970_129_6_a2,
     author = {G. V. Bushmanova and A. P. Norden},
     title = {A polar normalization of surfaces and a~congruence of circles in the conformal plane},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {22--32},
     publisher = {mathdoc},
     volume = {129},
     number = {6},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_1970_129_6_a2/}
}