1. C. C. Adams, Hyperbolic $3$-manifolds with two generators, Comm. Anal. Geom. 4 (1996), 181--206.
2. B. N. Apanasov, ``Nontriviality of Teichmüller space for Kleinian group in space'' in Riemann Surfaces and Related Topics: Proceedings of the 1978 Stony Brook Conference (Stony Brook, N.Y., 1978), ed. I. Kra and B. Maskit, Ann. of Math. Stud. 97, Princeton Univ. Press, Princeton, 1981, 21--31.
3. --. --. --. --., Deformations of conformal structures on hyperbolic manifolds, J. Differential Geom. 35 (1992), 1--20.
4. B. N. Apanasov and A. V. Tetenov, The existence of nontrivial quasiconformal deformations of Kleinian groups in space (in Russian), Dokl. Akad. Nauk SSSR 239 (1978), no. 1, 14--17.
5. English translation in Soviet Math. Dokl. 19 (1998), 242--245.