@article{DAN_1961_136_5_a0,
     author = {Ts. And\^o},
     title = {Certain classes of convex functions},
     journal = {Doklady Akademii Nauk},
     pages = {1007--1010},
     year = {1961},
     volume = {136},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_136_5_a0/}
}