1. Proof of a recursive program: Quicksort
2. Algorithm 64: Quicksort
3. Theories of Programming
4. Cormen TH, Leiserson CE, Rivest RL, Stein C. Introduction to algorithms. 3rd ed. Cambridge, MA: MIT Press; 2009.
5. Kleinberg J, Tardos E. Algorithm design. 1st ed. Boston, MA: Pearson Education, Inc.; 2006.