An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Feng Q, Purser JL, Zhen Z, Duncan PW.Feng Q, et al. Among authors: duncan pw.J Public Health (Oxf). 2011 Dec;33(4):543-50. doi: 10.1093/pubmed/fdr031. Epub 2011 Apr 22.J Public Health (Oxf). 2011.PMID: 21515901Free PMC article.
Lai SM, Duncan PW, Keighley J, Johnson D.Lai SM, et al. Among authors: duncan pw.J Rehabil Res Dev. 2002 Sep-Oct;39(5):589-96.J Rehabil Res Dev. 2002.PMID: 17642023Free article.