Nonlinear Differential Equations and Dynamical Systems (Universitext) Second Edition 1996 by Ferdinand Verhulst

For lecture courses that cover the classical theory of nonlinear differential equations associated with Poincare and Lyapunov and introduce the student to the ideas of bifurcation theory and chaos, this text is ideal. Its excellent pedagogical style typically consists of an insightful overview followed by theorems, illustrative examples, and exercises.