- https://docs.python.org/3/
- http://en.wikipedia.org/wiki/Programming_language_generations
- http://www.rff.com/flowchart_shapes.htm
- http://study.cs50.net
- Problem Solving with Algorithms and Data Structures By Brad Miller and David Ranum
- https://en.wikibooks.org
- https://rosettacode.org
- https://math.stackexchange.com/questions/2260/proof-for-formula-for-sum-of-sequence-123-ldotsn
- http://bigocheatsheet.com/
- https://www.youtube.com/watch?v=v4cd1O4zkGw
- https://en.wikipedia.org/wiki/Sorting_algorithm
- https://www.khanacademy.org/computing/computer-science/algorithms
- http://www.cs.wcupa.edu/rkline/ds/shell-comparison.html