Examples of Riemannian manifolds with positive curvature almost everywhere. Petersen, Peter; Wilhelm, Frederick — 1999 Geometry & Topology
Rigidity in non-negative curvature Luis Guijarro; Peter Petersen — 1997 Annales scientifiques de l'École Normale Supérieure
An excess sphere theorem Peter Petersen; Shun-Hui Zhu — 1993 Annales scientifiques de l'École Normale Supérieure
Geometric finiteness theorem via controlled topology (Erratum). K. Grove; Peter V Petersen; J.-Y. Wu — 1991 Inventiones mathematicae