%0 Journal Article
%A H. Katsuura 
%T Solid Angle Sum of a Tetrahedron
%J Journal for geometry and graphics
%D 2020
%P 29-34
%V 24
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JGG_2020_24_1_JGG_2020_24_1_a2/
%F JGG_2020_24_1_JGG_2020_24_1_a2