@article{SM_2007_198_3_a4,
     author = {I. V. Oseledets},
     title = {Lower bounds for separable approximations of the {Hilbert} kernel},
     journal = {Sbornik. Mathematics},
     pages = {425--432},
     publisher = {mathdoc},
     volume = {198},
     number = {3},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2007_198_3_a4/}
}