%0 Journal Article %A A. A. Ermolitskii %T The hat theorem and problems of the classification of structures on Riemannian manifolds %J Izvestiâ vysših učebnyh zavedenij. Matematika %D 2002 %P 27-31 %N 11 %I mathdoc %U http://geodesic.mathdoc.fr/item/IVM_2002_11_a2/ %G ru %F IVM_2002_11_a2