There is a function similar_text() in the PHP library. The documentation (http://php.net/manual/en/function.similar-text.php) tells me that "This calculates the similarity between two strings as described in Oliver [1993]."
Despite extensive searching, I can't find the paper that "Oliver [1993]" is referring to; nor any candidate for who "Oliver" might be. The PHP source is undocumented. The only other reference to Oliver 1993 is in a forum at http://www.codeguru.com/forum/showthread.php?t=41089, and I think that information is derived from the PHP documentation.
Anyone aware of what this might be?
Or this?
Programming Classics: Implementing the World's Best Algorithms (Hardback)
By (author) Ian OliverPublisher: Pearson Education
Published: 01 April 1994
ISBN 13: 9780131004139
ISBN 10: 013100413
http://www.bookdepository.co.uk/book/9780131004139/Programming-Classics
yes this should be it...