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@article{DAN_1985_283_5_a10, author = {G. G. Kazaryan}, title = {A numerical characteristic of linear differential operators with}, journal = {Doklady Akademii Nauk}, pages = {1068--1072}, publisher = {mathdoc}, volume = {283}, number = {5}, year = {1985}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1985_283_5_a10/} }
G. G. Kazaryan. A numerical characteristic of linear differential operators with. Doklady Akademii Nauk, Tome 283 (1985) no. 5, pp. 1068-1072. http://geodesic.mathdoc.fr/item/DAN_1985_283_5_a10/