1. The Gauss-Bonnet theorem for Riemannian polyhedra;Allendoerfer;Trans. Amer. Math. Soc.,1943
2. Critical points and curvature for embedded polyhedra;Banchoff;J. Differential Geom.,1967
3. Critical points and curvature for embedded polyhedra, II;Banchoff,1983
4. Gauss-Bonnet theorems for polyhedra;Brin;Uspekhi Mat. Nauk,1948
5. Lipschitz-Killing curvatures of angular partially ordered sets;Budach;Adv. Math.,1989