@article{Powell2006,
author = {Powell, L.M. and Slater, S. and Chaloupka, F.J. and Harper, D.},
title= {Availability of physical activity-related facilities and neighborhood demographic and socioeconomic characteristics: A national study},
year = {2006},
doi = {10.2105/AJPH.2005.065573},
journal = {American Journal of Public Health },
volume = {96},
number = {6},
pages = {1676--1680},
}