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@article{IVM_1971_2_a4, author = {R. M. Geidel'man}, title = {On the projective theory of pairs of line congruences}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {42--52}, publisher = {mathdoc}, number = {2}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1971_2_a4/} }
R. M. Geidel'man. On the projective theory of pairs of line congruences. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 2 (1971), pp. 42-52. http://geodesic.mathdoc.fr/item/IVM_1971_2_a4/