APA (7th ed.) Citation

SJ, S., JN, R., JC, B., ND, R., PJ, S., LH, E., . . . Epstein, L. H. (2009). Effect of peers and friends on youth physical activity and motivation to be physically active. Journal of Pediatric Psychology, 34(2), 217. https://doi.org/10.1093/jpepsy/jsn071

Chicago Style (17th ed.) Citation

SJ, Salvy, et al. "Effect of Peers and Friends on Youth Physical Activity and Motivation to Be Physically Active." Journal of Pediatric Psychology 34, no. 2 (2009): 217. https://doi.org/10.1093/jpepsy/jsn071.

MLA (9th ed.) Citation

SJ, Salvy, et al. "Effect of Peers and Friends on Youth Physical Activity and Motivation to Be Physically Active." Journal of Pediatric Psychology, vol. 34, no. 2, 2009, p. 217, https://doi.org/10.1093/jpepsy/jsn071.