There is no required textbook for this course. A list of a few recommended textbooks can be found below.
Textbooks in Applied Mathematics and Applications
Whitham, G. B. Linear and Nonlinear Waves. New York, NY: Wiley, 1999. ISBN: 9780471359425.
Kevorkian, J. Partial Differential Equations: Analytical Solution Techniques. Texts in Applied Mathematics, vol. 35. 2nd ed. New York, NY: Springer, 2000. ISBN: 9780387986050.
Hinch, E. J. Perturbation Methods. Cambridge Texts in Applied Mathematics. Cambridge, UK: Cambridge University Press, 1991. ISBN: 9780521378970.
Guenther, Ronald B., and John W. Lee. Partial Differential Equations of Mathematical Physics and Integral Equations. New York, NY: Dover Publications, 1996. ISBN: 9780486688893.
Other Textbooks at a Similar Level
Debnath, Lokenath. Nonlinear Partial Differential Equations for Scientists and Engineers. Boston, MA: Birkhäuser, 1997. ISBN: 9780817639020.
Carrier, George F., and Carl E. Pearson. Partial Differential Equations: Theory and Technique. 2nd ed. Boston, MA: Academic Press, 1988. ISBN: 9780121604516.
Barenblatt, G. I. Scaling, Self-Similarity, and Intermediate Asymptotics. Cambridge Texts in Applied Mathematics, vol. 14. Cambridge, UK: Cambridge University Press, 1996. ISBN: 9780521435222.
Levine, Harold. Partial Differential Equations. AMS/IP Studies in Advanced Mathematics, vol. 6. Providence, RI: American Mathematical Society, 1997. ISBN: 9780821807750.
Drazin, P. G., and R. S. Johnson. Solitons: An Introduction. Cambridge Texts in Applied Mathematics. Cambridge, UK: Cambridge University Press, 1989. ISBN: 9780521336550.
Books with More Emphasis on Rigorous Mathematical Theory
Evans, Lawrence C. Partial Differential Equations. Graduate Studies in Mathematics, vol. 19. Providence, RI: American Mathematical Society, 1998. ISBN: 9780821807729.
DiBenedetto, Emmanuele. Partial Differential Equations. Boston, MA: Birkhäuser, 1995. ISBN: 9780817637088.
Garabedian, Paul. Partial Differential Equations. Providence, RI: AMS Chelsea, 1998. ISBN: 9780821813775.