1. V. N. Berestovskii, “Similarity Homogeneous Locally Complete Spaces with Intrinsic Metric,” Izv. Vyssh. Uchebn. Zaved., Mat., No. 11, 3–22 (2004) [Russian Mathematics 48 (11), 1–19 (2004)].
2. A. G. Vainstein, U. M. Gorelik, and V. A. Efremovich, “Fibration of the Lobachevskii Plane,” Dokl. Akad. Nauk SSSR 241(2), 269–271 (1978).
3. M. Bestvina, “ℝ-trees in Topology, Geometry and Group Theory,” in Handbook of Geometric Topology, Ed. by R. J. Daverman and R. B. Sher (North-Holland, Amsterdam, London, New York: NY: Elsevier Science, 2002), pp. 55–91.
4. M. Gromov, “Hyperbolic Manifolds, Groups, and Actions,” in Proc. of the 1978 Stony Brook Conference (Princeton Univ. Press, 1981), pp. 182–213.
5. C. Webster and A. Winchester, “Boundaries of Hyperbolic Metric Spaces,” Pac. J. Math. 221(1), 147–158 (2005).