Hi. This is from "Batman: The Ultimate Guide to the Dark Knight" by Scott Beaty, one of those DK books.
From Page 11, the paragraph titled "WALKABOUT".
"At age 14, Bruce Wayne began his global sojourn., attending courses at Cambridge, the Sorbonne, and other European universities. Beyond academia, Bruce acquired more practical skills. Frenchman Henri Ducard made him an apprentice in manhunting. The ninja Kirigi schooled Bruce in stealth and the ways of the shadow warrior. African Bushmen taught hunting techniques, while Nepalese monks revealed healing arts. And so it went for 12 years as Bruce matured into manhood."
All I can help you with.
Brucie boy is supposed to have had a few trainers/senseis during his world tour before he donned the cape. Even in the movie it's quite clear that he's very accomplished at martial arts before he meets Ras, as he fights Ras having first arrived at his fortress, notice Ras naming each and every move Bruce uses.