@article{MZM_1991_49_6_a9,
     author = {O. G. Parfenov},
     title = {Estimates of the singular numbers of {Hankel} operators},
     journal = {Matemati\v{c}eskie zametki},
     pages = {82--86},
     publisher = {mathdoc},
     volume = {49},
     number = {6},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_6_a9/}
}