00294nam a2200121Ia 4500082001700000100002000017245002600037260003600063300002100099490004200120500000500162700000500167  a516bP484.RG  aPetersen, Peter  aRiemannian geometryb  aNew YorkbSpringer-Verlagc1998  axvi, 432p. Index  aGraduate texts in mathematics, v. 171  a  a