@article{SEMR_2010_7_a18,
     author = {G. A. Akishev},
     title = {On the exact estimations of the best $M$--terms approximation of the {Besov} class},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {255--274},
     publisher = {mathdoc},
     volume = {7},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2010_7_a18/}
}