GEOMETRIAE DEDICATA, cilt.138, ss.99-115, 2009 (SCI İndekslerine Giren Dergi)
We obtain a new version of Schlafli differential formula based on edge lengths for the volume of a tetrahedron in hyperbolic and spherical 3-spaces, by using the edge matrix of a hyperbolic( or spherical) tetrahedron and its submatrix.