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@article{IVM_1987_4_a13, author = {V. A. Tihonov}, title = {On fields with $\nabla$-conjugate $m$-directions in a~space with affine connection}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {71--75}, publisher = {mathdoc}, number = {4}, year = {1987}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1987_4_a13/} }
V. A. Tihonov. On fields with $\nabla$-conjugate $m$-directions in a~space with affine connection. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 4 (1987), pp. 71-75. http://geodesic.mathdoc.fr/item/IVM_1987_4_a13/