Pilot Evaluation of the Impact of Lottery-Based Incentives on Engagement Levels of Male Low SES Vocational Students With an mHealth App. - Raoul C. Y. Nuijten; Pieter Van Gorp; Juup Hietbrink; Pascale Le Blanc; Astrid Kemperman; Pauline van den Berg; Monique Simons (Frontiers Digit. Health, 2021)