Intrinsic motivation in two exercise interventions: Associations with fitness and body composition
Health Psychology (2016) - Comment
pubmed: 26389719  doi: 10.1037/hea0000260  issn: 1930-7810  issn: 0278-6133 

Cecilie Thøgersen-Ntoumani, Sam O. Shepherd, Nikos Ntoumanis, Anton J. M. Wagenmakers, Christopher S. Shaw