Community Walks: a cluster randomized controlled trial of a multilevel physical activity intervention for low income public housing residents oleh Lisa M. Quintiliani, Julien Dedier, Marislena Amezquita, Melibea Sierra-Ruiz, Dariela Romero, Jennifer Murillo, Sarah Mahar, Melody Goodman, John B. Kane, Doreen Cummings, Timothy G. Woolley, Iolando Spinola, Scott E. Crouter