Often two age groups (U15, U16) merged at this age and form a U15 U16 floorball team. Floorball drills for U15 and U16 can be found on Flrball.com in the form of eBooks or books.
Buy the floorball books from online bookstores like Amazon, Wallmart, Alibris, AbeBooks, Bokus, Bookshop, BoD etc. or search through Google