@article{CMFD_2010_36_a9,
     author = {V. A. Popov and A. L. Skubachevskii},
     title = {A priori estimates for elliptic differential-difference operators with degeneration},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {125--142},
     publisher = {mathdoc},
     volume = {36},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2010_36_a9/}
}