@article{SM_1971_13_3_a8,
     author = {A. P. Bulanov},
     title = {Rational approximations to convex functions with given modulus of con\-tinuity},
     journal = {Sbornik. Mathematics},
     pages = {473--490},
     year = {1971},
     volume = {13},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_13_3_a8/}
}