@article{IVM_1969_3_a4,
     author = {F. G. Nasibov},
     title = {The order of the best approximations of certain classes of functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {35--41},
     publisher = {mathdoc},
     number = {3},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1969_3_a4/}
}