中国科学院数学与系统科学研究院期刊网
Discreteness Criteria for Subgroups of Isometry Group of Pinched Hadamard Manifold
Bin Lin DAI
Acta Mathematica Sinica, Chinese Series . 2004, (6): 1217 -122 .  DOI: 10.12386/A2004sxxb0152