Kapovich, Michael Max Planck Institute for Mathematics, Max Planck Society;
https://doi.org/10.4310/jdg/1649953550 (Publisher version)
1808.01602.pdf (Preprint), 130KB
Kapovich, M. (2022). A note on Selberg's lemma and negatively curved Hadamard manifolds. Journal of Differential Geometry, 120(3), 519-513. doi:10.4310/jdg/1649953550.