@article{DAN_1970_194_5_a6,
     author = {I. I. Ibragimov and F. G. Nasibov},
     title = {The estimation of the best approximation of a summable function on the real axis by means of entire functions of finite degree},
     journal = {Doklady Akademii Nauk},
     pages = {1013--1016},
     publisher = {mathdoc},
     volume = {194},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_194_5_a6/}
}