Paradis, K. F., L. M. Cooke, L. J. Martin, and C. R. Hall. “Just Need Some Satisfaction: Examining the Relationship Between Passion for Exercise and the Basic Psychological Needs”. The Health & Fitness Journal of Canada, vol. 7, no. 2, May 2014, pp. 15-28, doi:10.14288/hfjc.v7i2.166.