@article{TM_1972_117_a13,
     author = {M. K. Potapov},
     title = {The study of certain classes of functions by means of ``angular''' approximation},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {256--291},
     publisher = {mathdoc},
     volume = {117},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1972_117_a13/}
}