@article{IM2_1991_36_2_a10,
     author = {\`E. M. Galeev},
     title = {Kolmogorov widths of classes of periodic functions of one and several variables},
     journal = {Izvestiya. Mathematics},
     pages = {435--448},
     year = {1991},
     volume = {36},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1991_36_2_a10/}
}