%0 Journal Article %A I. V. Stasyuk %A O. V. Velichko %T Bose–Einstein condensation in the excited band and the energy spectrum of the Bose–Hubbard model %J Teoretičeskaâ i matematičeskaâ fizika %D 2011 %P 571-583 %V 168 %N 3 %U http://geodesic.mathdoc.fr/item/TMF_2011_168_3_a15/ %G ru %F TMF_2011_168_3_a15