M Boileau, S
Maillot, J Porti, Three-dimensional orbifolds and
their geometric structures, Panoramas et Synthèses 15,
Société Mathématique de France (2003) MR2060653
2
M Boileau, J
Porti, Geometrization of 3–orbifolds of cyclic
type, Astérisque (2001) 208 MR1844891
Appendix A: Limit of hyperbolicity for spherical
3–orbifolds by M Heusener and J Porti
3
D A Derevnin,
A D Mednykh, Discrete extensions of the Lanner
groups, Dokl. Akad. Nauk 361 (1998) 439–442 MR1693083
Translation in: Dokl. Math. 58 (1998), no. 1, 78–80
4
D A Epstein, C
Petronio, An exposition of Poincaré's polyhedron
theorem, Enseign. Math. (2) 40 (1994) 113–170
MR1279064
5
F W Gehring,
G J Martin, Stability and extremality in Jø
rgensen's inequality, Complex Variables Theory Appl. 12
(1989) 277–282 MR1040927
6
F W Gehring,
G J Martin, Chebyshev polynomials and discrete
groups, from: "Proceedings of the Conference on Complex
Analysis (Tianjin, 1992)", Conf. Proc. Lecture Notes Anal., I,
Int. Press, Cambridge, MA (1994) 114–125 MR1343502
