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@article{IVM_1971_11_a10, author = {L. Z. Kruglyakov}, title = {Generalized pseudofocal families of $d$-planes in~$P_N$}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {78--84}, publisher = {mathdoc}, number = {11}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1971_11_a10/} }
L. Z. Kruglyakov. Generalized pseudofocal families of $d$-planes in~$P_N$. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 11 (1971), pp. 78-84. http://geodesic.mathdoc.fr/item/IVM_1971_11_a10/