Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MZM_1971_9_3_a1, author = {F. I. Kagan}, title = {Lifts as isomorphisms of graded algebras}, journal = {Matemati\v{c}eskie zametki}, pages = {239--247}, publisher = {mathdoc}, volume = {9}, number = {3}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1971_9_3_a1/} }
F. I. Kagan. Lifts as isomorphisms of graded algebras. Matematičeskie zametki, Tome 9 (1971) no. 3, pp. 239-247. http://geodesic.mathdoc.fr/item/MZM_1971_9_3_a1/