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@article{TM_1980_147_a3, author = {N. M. Ivochkina}, title = {Second-order differential equations with $d$-elliptic operators}, journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova}, pages = {40--56}, publisher = {mathdoc}, volume = {147}, year = {1980}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TM_1980_147_a3/} }
N. M. Ivochkina. Second-order differential equations with $d$-elliptic operators. Trudy Matematicheskogo Instituta imeni V.A. Steklova, Boundary value problems of mathematical physics. 10, Tome 147 (1980), pp. 40-56. http://geodesic.mathdoc.fr/item/TM_1980_147_a3/