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@article{DAN_1960_134_4_a4, author = {P. I. Lizorkin}, title = {The {Dirichlet} principle for the {Beltrami} equation in a semi-space}, journal = {Doklady Akademii Nauk}, pages = {761--764}, publisher = {mathdoc}, volume = {134}, number = {4}, year = {1960}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1960_134_4_a4/} }
P. I. Lizorkin. The Dirichlet principle for the Beltrami equation in a semi-space. Doklady Akademii Nauk, Tome 134 (1960) no. 4, pp. 761-764. http://geodesic.mathdoc.fr/item/DAN_1960_134_4_a4/