Ordinary Differential Equations (Dover Books on Mathematics)

very good quality, better than new paperback ones!

This "advance study" of O.D.E. has absolutely nothing to do with O.D.E., but everything to do with Set Theory. Just reading it is a nightmare.

I studied this book many years ago as a graduate student, it was the textbook for the ODEs course at that time. it belongs to those ODEs books which avoids references to PDE so it is an ODE book aiming to dynamical systems. Its content is not pedagogically distributed so it is a relatively hard book to learn from it. Moreover, it is a little bit outdated, so I would say that it is a four star book

The unique problem is the fontsize of the characters. The characters are very, very short and it's difficult to read even for those who need wear glasses. But the content is very good. Dover Publications should make a new version of this book increasing the text font size.