@article{SM_1967_2_2_a2,
     author = {B. P. Paneyakh},
     title = {Pseudodifferential operators of constant strength in the main},
     journal = {Sbornik. Mathematics},
     pages = {179--198},
     publisher = {mathdoc},
     volume = {2},
     number = {2},
     year = {1967},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1967_2_2_a2/}
}