Book recommendation for ordinary differential equations This question has been posted before, but I need book with specific qualifications. I do not need books for engineers, book that is centered around calculations and stuff. I need to find a book that is theoretical, proves the statements and has good presentation of the theoretical structure. I have had the book by Tenenbaum, I did not like it. I would be very very thankful if someone shared their knowledge with us about this matter. 

I would like to add "Differential Equations With Applications and Historical Notes by George Simmons" to this list. This is a very well written text on ODEs and very approachable and explains concepts very clearly.
