Why do you play World of Warcraft? An in-depth exploration of self-reported motivations to play online and in-game behaviours in the virtual world of Azeroth. - Joël Billieux; Martial Van der Linden; Sophia Achab; Yasser Khazaal; Laura Paraskevopoulos; Daniele Zullino; Gabriel Thorens (Comput. Hum. Behav., 2013)