Happiness among dentists: a multi-scale, multi-national study from 21 countries - Alhajj, Mohammed Nasser; Omar, Ridwaan; Khader, Yousef; Celebić, Asja; El Tantawi, Maha; Folayan, Morenike Oluwatoyin; Al-Maweri, Sadeq Ali; Halboub, Esam; Alkheraif, Abdulaziz A.; Sousa Neto, Manoel Damião de; Vukovic, Ana; Camargo, Rafael Verardino de (International Dental Journal, 2020)