[Fwibos]

Well, I am not the Author, but JFGI-ing the thing points to wikipedia, which has no citation.

If I were to hazard a guess, I'd say it came from one of the Nonfiction books in the bibliography of Martial Arts. Not sure if I am allowed to quote it, but it likely would be:

Draeger, Donn F. and Smith, Robert W. Comprehensive Asian Fighting Arts

You might wan t to try and PM the Authors. They are on the forums, but infrequently.