Suggestion or help to choose a book for theory of ODE

Question

I have recently had a course in theory of ordinary differential equations , I have learned main ideas and now I want to study theory of ODE from a book for filling gaps. I have chose three books but I don't know which one is better they are

1.coddingtone levinson

2.jane cronin

3.Jack hale

Can someone help me to choose a good one or suggest an other book?

Answer 1

Personally I have two that I like

1. Differential Equations with Applications and Historical Notes, Simmons, G.F.Link to Amazon here

2. Elementary Differential Equations and Boundary Value Problems, Boyce, W.E. Link to Amazon here