1. U. Haagerup and H.J. Munkholm, Simplices of maximal volume in hyperbolic n-space, to appear (available as preprint from Odense University, Denmark).
2. J.W. Milnor, Computation of volume, chapter 7 in [4].
3. Ann.Math.Studies;G.D. Mostow,1973
4. W.P. Thurston, The geometry and topology of 3-manifolds, lecture notes, Princeton University 1977/78.