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@article{DAN_1994_337_3_a4, author = {V. V. Katrakhov and S. M. Sitnik}, title = {A composition method for constructing $B$-elliptic, $B$-hyperbolic}, journal = {Doklady Akademii Nauk}, pages = {307--311}, publisher = {mathdoc}, volume = {337}, number = {3}, year = {1994}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1994_337_3_a4/} }
V. V. Katrakhov; S. M. Sitnik. A composition method for constructing $B$-elliptic, $B$-hyperbolic. Doklady Akademii Nauk, Tome 337 (1994) no. 3, pp. 307-311. http://geodesic.mathdoc.fr/item/DAN_1994_337_3_a4/