@article{DE_1991_27_8_a12,
     author = {I. A. Kipriyanov and A. A. Kulikov},
     title = {Fundamental solutions of $B$-hypo-elliptic equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1387--1395},
     publisher = {mathdoc},
     volume = {27},
     number = {8},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_8_a12/}
}