@article{EMJ_2015_6_4_a3,
     author = {V. N. Margaryan and H. G. Ghazaryan},
     title = {Almost hypoelliptic operators with constant powers},
     journal = {Eurasian mathematical journal},
     pages = {29--43},
     publisher = {mathdoc},
     volume = {6},
     number = {4},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EMJ_2015_6_4_a3/}
}