- Regular Expression HOWTO: https://docs.python.org/2/howto/regex.html
- Regular Expressions – JavaScript: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
- Python Regular Expressions: https://developers.google.com/edu/python/regular-expressions
- Online Regex Tester and Debugger: https://regex101.com/
- Regular Expressions Cookbook: 2nd Edition, 2012 by Jan Goyvaerts and Steven Levithan
- Regular Expressions References: https://regexone.com/references/python
- Regular Expressions – Information: http://www.regular-expressions.info/python.html