%0 Journal Article %A A. V. Litavrin %T Endomorphisms of some groupoids of order $k+k^2$ %J The Bulletin of Irkutsk State University. Series Mathematics %D 2020 %P 64-78 %V 32 %I mathdoc %U http://geodesic.mathdoc.fr/item/IIGUM_2020_32_a4/ %G en %F IIGUM_2020_32_a4