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@article{IVM_1968_4_a12, author = {S. E. Tychinina}, title = {Stratifiable pairs of congruences of planes in $P_5$}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {77--86}, publisher = {mathdoc}, number = {4}, year = {1968}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1968_4_a12/} }
S. E. Tychinina. Stratifiable pairs of congruences of planes in $P_5$. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 4 (1968), pp. 77-86. http://geodesic.mathdoc.fr/item/IVM_1968_4_a12/