%0 Journal Article %A Andrey V. Litavrin %T On the bipolar classification of endomorphisms of a groupoid %J Žurnal Sibirskogo federalʹnogo universiteta. Matematika i fizika %D 2024 %P 378-387 %V 17 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/JSFU_2024_17_3_a8/ %G en %F JSFU_2024_17_3_a8