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@article{DE_1985_21_3_a28, author = {V. M. Filippov}, title = {A general approach to symmetrization of differential operators}, journal = {Differencialʹnye uravneni\^a}, pages = {539--541}, publisher = {mathdoc}, volume = {21}, number = {3}, year = {1985}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1985_21_3_a28/} }
V. M. Filippov. A general approach to symmetrization of differential operators. Differencialʹnye uravneniâ, Tome 21 (1985) no. 3, pp. 539-541. http://geodesic.mathdoc.fr/item/DE_1985_21_3_a28/