%0 Journal Article %A H. Eliopoulos %T Some properties of differentiable structures defined by nilpotent operators of degree r %J Δελτίο της Ελληνικής Μαθηματικής Εταιρίας %D 1966 %P 81-94 %V 07 %N A %U http://geodesic.mathdoc.fr/item/DEME_1966_07_A_a6/ %G gr %F DEME_1966_07_A_a6