Dynamical Systems V: Bifurcation Theory and Catastrophe Theory

Modern Geometry— Methods and Applications: Part II: The Geometry and Topology of Manifolds

Modern Geometry - Methods and Applications: Part I. The Geometry of Surfaces, Transformation Groups, and Fields

Introduction to Riemannian Manifolds: Edition 2

Analysis IV: Linear and Boundary Integral Equations

Geometry II: Spaces of Constant Curvature

Foundations of the Classical Theory of Partial Differential Equations