@article{DE_1981_17_5_a13,
     author = {M. B. Muratbekov},
     title = {Coercive estimates for a higher-order differential operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {893--901},
     publisher = {mathdoc},
     volume = {17},
     number = {5},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_5_a13/}
}