@article{SM_1969_8_1_a2,
     author = {Yu. V. Egorov},
     title = {On~a~class of pseudodifferential operators},
     journal = {Sbornik. Mathematics},
     pages = {53--71},
     year = {1969},
     volume = {8},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1969_8_1_a2/}
}