%0 Journal Article %A A. A. Kosov %A E. I. Semenov %T First integrals and periodic solutions of a~system with power nonlinearities %J Sibirskij žurnal industrialʹnoj matematiki %D 2018 %P 47-60 %V 21 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/SJIM_2018_21_1_a4/ %G ru %F SJIM_2018_21_1_a4