@article{DAN_1970_190_1_a1,
     author = {A. P. Bulanov},
     title = {The best rational approximations of convex functions and functions of finite variation},
     journal = {Doklady Akademii Nauk},
     pages = {13--14},
     publisher = {mathdoc},
     volume = {190},
     number = {1},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_190_1_a1/}
}