"Mathematical Statistics and Data Analysis" by John A. Rice
"All of Statistics: A Concise Course in Statistics" by Larry Wasserman
"Pattern Recognition and Machine Learning" by Christopher M. Bishop
"The Elements of Statistical Learning" by T. Hastie et al http://www-stat.stanford.edu/~tibs/ElemStatLearn/
"Information Theory, Inference, and Learning Algorithms", David McKay http://www.inference.phy.cam.ac.uk/itprnn/book.html
"Introduction to Information Retrieval" - Manning et al. http://nlp.stanford.edu/IR-book/information-retrieval-book.h...
"The Algorithm Design Manual, 2nd Edition" - Steven Skiena http://www.algorist.com/