Mathematical Physics- Michael T. Vaughan.

A First Course In String Theory- Barton Zwiebach. Cambridge.

Multivariable Calculus - Clark Bray

Curvature in Mathematics and Physics (Dover Books on Mathematics)

Mathematics of Classical and Quantum Physics (Dover Books on Physics)

Lot Of 6 Dover Books on Math, Physics & Logic Books

Mathematics of Classical and Quantum Physics (Dover Books on Physics) - GOOD

Mathematics for Physicists (Dover Books on Physics) - Dennery, Philippe