http://stackoverflow.com/questions/9011592/in-regular-expressions-what-is-a-backtracking-back-referencing http://stackoverflow.com/questions/9011592/in-regular-

http://stackoverflow.com/questions/9011592/in-regular-expressions-what-is-a-backtracking-back-referencing http://stackoverflow.com/questions/9011592/in-regular-expres...