@article{DAN_1971_198_6_a8,
     author = {M. F. Timan and G. Gaimnazarov},
     title = {Best approximations and absolute convergence of {Fourier{\textendash}Haar} series},
     journal = {Doklady Akademii Nauk},
     pages = {1280--1282},
     year = {1971},
     volume = {198},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_198_6_a8/}
}