@article{IM2_2007_71_3_a7,
     author = {E. M. Skorikov},
     title = {The information {Kolmogorov} width and some exact inequalities between widths},
     journal = {Izvestiya. Mathematics},
     pages = {603--627},
     year = {2007},
     volume = {71},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2007_71_3_a7/}
}