@article{SM_1971_13_2_a0,
     author = {V. V. Grushin},
     title = {On a~class of elliptic pseudodifferential operators degenerate on a~submani\-fold},
     journal = {Sbornik. Mathematics},
     pages = {155--185},
     year = {1971},
     volume = {13},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_13_2_a0/}
}