TY - JOUR AU - E. T. Ivlev TI - Certain geometric forms associated with a~family of lines and planes in $^lS_n$ JO - Izvestiâ vysših učebnyh zavedenij. Matematika PY - 1971 SP - 35 EP - 44 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/IVM_1971_1_a4/ LA - ru ID - IVM_1971_1_a4 ER -