The relationship of physical activity and the built environment within the context of self-determination theory
Annals of Behavioral Medicine (2011) - Comment
pubmed: 21818529  doi: 10.1007/s12160-011-9292-y  issn: 1532-4796  issn: 0883-6612 

Jennifer L. Gay, Ruth P. Saunders, Marsha Dowda