*[Mathematical Logic - an Introduction](http://www.ii.uib.no/~michal/und/i227/book/book.pdf)(PDF)
*[Bayesian Methods for Hackers](https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers)
*[Introduction to Statistical Thought](http://www.math.umass.edu/~lavine/Book/book.html)
*[Mathematics for Computer Science](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-042j-mathematics-for-computer-science-fall-2010/readings/)
*[Mathematics for Computer Science (November 2013 Version)](http://courses.csail.mit.edu/6.042/fall13/mcs.pdf)(PDF) - Eric Lehman
*[Calculus Made Easy](http://www.gutenberg.org/ebooks/33283)(PDF) - Silvanus P. Thompson
*[Category Theory for Computing Science](http://www.math.mcgill.ca/triples/Barr-Wells-ctcs.pdf)(PDF)
*[Essentials of Metaheuristics](http://cs.gmu.edu/~sean/book/metaheuristics/) by Sean Luke
*[Advanced Data Analysis from an Elementary Point of View](http://www.stat.cmu.edu/~cshalizi/ADAfaEPoV/)