@article{DE_1979_15_7_a18,
     author = {I. A. Shishmarev},
     title = {The {Cauchy} problem for hypoelliptic systems and representation of the interaction},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1337--1339},
     publisher = {mathdoc},
     volume = {15},
     number = {7},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_7_a18/}
}