Book Recommendations about Systems of Differential Equations with Variable Coefficients

Question

Do you have book suggestions about systems of differential equations with variable coefficients?

All suggestions about

-homogeneous/Nonhomogeneous

-Linear/nonlinear

systems of DEs. (ODE & PDE) (all from beginner level to advanced level)

I think this post will be useful for many researchers.

Thanks for interest.

Answer 1

What about Calculus A complete course? I think it covers all these subjects, unless I am mistaken about the terminology.