Apart from Keisler, mentioned there, I think there are 2 lovely and rigurous references especially appropriate for anyone with a CS background: * Henle & Klein

Apart from Keisler, mentioned there, I think there are 2 lovely and rigurous references especially appropriate for anyone with a CS background: * Henle & Kleinberg [1] * Hubbard & Hubbard [2] Both are breathtakingly beautiful. Henle & Kleinberg is small and neat. Hubbard & Hubbard integrates calculus and linear algebra. In some ways it reminds me of SICP, described by Peter Norvig as "[...] a rich framework onto which you can add new learning over a career". [3] [1] https://books.google.co.uk/books/about/Infinitesimal_Calculus.html?id=nalhCn80D08C&redir_esc=y https://books.google.co.uk/books/about/Infinitesimal_Calculu... [2] http://matrixeditions.com/5thUnifiedApproach.html http://matrixeditions.com/5thUnifiedApproach.html [3] http://www.amazon.com/review/R403HR4VL71K8 http://www.amazon.com/review/R403HR4VL71K8