I'm selling a few undergraduate math/engineering textbooks that hopefully can still be useful! Feel free to send your best offer as well. Title: Elementary Differential Equations and Boundary Value Problems 9th (ninth) Edition by Boyce, William E., DiPrima, Richard C. published by Wiley (2008) Link: https://www.amazon.com/Elementary-Differential-Equations-Boundary-published/dp/B00E28KIJO/ref=mt_hardcover?_encoding=UTF8&me=&qid= Condition: Great Price: $40 Title: Linear Algebra and Its Applications (3rd Edition) by David C. Lay Link: https://www.amazon.com/Linear-Algebra-Its-Applications-3rd/dp/0201709708/ref=sr_1_1?s=books&ie=UTF8&qid=1535263341&sr=1-1&keywords=linear+algebra+and+its+applications+3rd+edition Condition: Good Price: $20 Title: Vector Calculus Fifth Edition by Jerrold E. Marsden (Author), Anthony Tromba (Author) Link: Condition: Great Price: $20