%0 Journal Article %A Valery Dryuma %T On limit cycles of polynomial systems of the first-order ODE's %J Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica %D 2019 %P 113-126 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/BASM_2019_2_a6/ %G en %F BASM_2019_2_a6