In Kiev, Friedmann joined the Mathematical Society which had among its members Ch T Bialobzeski, P V Voronets, B N Delone, D A Grave, A P Kotelnikov, V P Linnik (I V Linnik 's father) and O Yu Schmidt. In April 1917 the Central Aeronautical Station moved to Moscow, and Friedmann moved there.
Sa Kiev, Friedmann sumali sa matematika Lipunan na kung saan ay kabilang sa mga kasapi nito Ch T Bialobzeski, PV Voronets, bn Delone, DA libingan, AP Kotelnikov, VP Linnik (IV Linnik 's ama) at O Schmidt Yu. Sa Abril 1917 sa Central Aeronautical Station inilipat sa Moscow, at Friedmann inilipat doon.