%0 Journal Article
%A Peter Lappan
%T The spherical derivative and normal functions
%J Annales Fennici Mathematici
%D 1977
%P 301-310
%V 3
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1977.0312/
%R 10.5186/aasfm.1977.0312
%G en
%F AFM_1977_3_2_a9