@article{SM_1978_34_3_a6,
     author = {B. V. Fedosov},
     title = {A~periodicity theorem in the algebra of symbols},
     journal = {Sbornik. Mathematics},
     pages = {382--410},
     publisher = {mathdoc},
     volume = {34},
     number = {3},
     year = {1978},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1978_34_3_a6/}
}