Environmental and Policy Determinants of Physical Activity in the United States
Ross C. Brownson, PhD,
Elizabeth A. Baker, PhD, MPH,
Robyn A. Housemann, PhD, MPH,
Laura K. Brennan, MPH and
Stephen J. Bacak, MPH
The authors are with the Department of Community Health and Prevention Research Center, School of Public Health, Saint Louis University, St. Louis, Mo.