@article{DE_1970_6_9_a13,
     author = {A. S. Fokht},
     title = {Boundary estimates of the derivatives of the solutions of a certain class of hypoelliptic equations in the $L_2$ metric},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1673--1682},
     publisher = {mathdoc},
     volume = {6},
     number = {9},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_9_a13/}
}