@article{SM_1969_9_3_a6,
     author = {Ya. I. Zhitomirskii},
     title = {On~differential operators of infinite order in spaces of type~$S$},
     journal = {Sbornik. Mathematics},
     pages = {379--388},
     publisher = {mathdoc},
     volume = {9},
     number = {3},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1969_9_3_a6/}
}