%0 Journal Article
%A González, M. O.
%T A spherical representation of the real directional derivative.
%J Gaceta matemática
%D 1976
%P 25-29
%V 28
%N 1-2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/GAMA_1976_1976_1_a3/
%G en
%F GAMA_1976_1976_1_a3