%0 Journal Article
%A S. Dolecki
%A G. H. Greco
%T Tangency vis-à-vis Differentiability by Peano, Severi and Guareschi
%J Journal of convex analysis
%D 2011
%P 301-339
%V 18
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JCA_2011_18_2_JCA_2011_18_2_a0/
%F JCA_2011_18_2_JCA_2011_18_2_a0