Preadolescent students' engagement with an mhealth intervention fostering social comparison for health behavior change : Crossover experimental study

by Nuijten, Raoul Ceasar Yannic, van Gorp, Pieter, Borghouts, Tom, Le Blanc, Pascale, van den Berg, Pauline, Kemperman, Astrid, Hadian, Ehsan, Simons, Monique