Partial Differential Equations, Applied Nonlinear Equations, and Classical Mechanics

Red_CCF

Hi

I'm currently in undergrad and I'm wondering what is a good textbook for Partial Differential Equations, Applied Nonlinear Equations for self-study (difficulty level 3rd-4th year aerospace).

I'm also looking for a good Classical Mechanics/Dynamics textbook for 2nd-3rd year engineering student.

Thanks.