When you want to find duplicates or candidates of duplicates it's not easy to solve.

Therefor there are some methods invented to give a nice idea if two string match or not.

One method is the Levenshtein Method:

The Levenshtein distance is a string metric for measuring the difference between two sequences. Informally, the Levenshtein distance between two words is the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other. It is named after the Soviet mathematician Vladimir Levenshtein, who considered this distance in 1965.