1. On convex polyhedra in Lobachevskii spaces;Andreev;Math. USSR Sb.,1970
2. Convex polyhedra of finite volume in Lobachebskii space;Andreev;Math. USSR Sb.,1970
3. Matrices de Gram y espacios de ángulos diédricos de poliedros;Diaz,1996
4. A characterization of Gram matrices of polytopes;Díaz,1997
5. Convex Polytopes;Grünbaum,1967