Rosamond Wayne D, Reeves Mathew J, Johnson Anna, Evenson Kelly R
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill 27514, USA.
Am J Prev Med. 2006 Dec;31(6 Suppl 2):S230-4. doi: 10.1016/j.amepre.2006.08.008. Epub 2006 Nov 7.