@article{VMUMM_1999_6_a0,
     author = {A. M. Sedletskii},
     title = {Approximation properties of systems of exponentials in {Sobolev} spaces},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {3--8},
     year = {1999},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1999_6_a0/}
}