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@article{IVM_1973_2_a11, author = {V. S. Fokin}, title = {Weakly stratifiable pairs of line congruences}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {91--98}, publisher = {mathdoc}, number = {2}, year = {1973}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1973_2_a11/} }
V. S. Fokin. Weakly stratifiable pairs of line congruences. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 2 (1973), pp. 91-98. http://geodesic.mathdoc.fr/item/IVM_1973_2_a11/