I have completed Calc 1 - 3 Diff EQ and Linear Algebra and have a degree in Mechanical Eng. I have some free time this summer and am looking for suggestions on a book that deals with applied math at a level somewhat above the courses I have listed. I would like to be challenged and have to material relate to my background listed above. My only thought right now is Div Grad Curl and all that by Schey. I would like some more ideas to choose from. Thanks!