(2007). 90 world-class activities by 90 world-class trainers. San Francisco, CA: J. Wiley & Sons.
Παραπομπή Chicago Style90 World-class Activities By 90 World-class Trainers. San Francisco, CA: J. Wiley & Sons, 2007.
Παραπομπή MLA90 World-class Activities By 90 World-class Trainers. San Francisco, CA: J. Wiley & Sons, 2007.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.