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.
He F, Zhou JY, Hu YQ, Sun F, Yang J, Lin S, Fung WK.He F, et al. Among authors: zhou jy.Am J Epidemiol. 2011 Jul 15;174(2):226-33. doi: 10.1093/aje/kwr056. Epub 2011 Jun 1.Am J Epidemiol. 2011.PMID: 21633117Free PMC article.
Pan DD, Xiong WJ, Zhou JY, Pan Y, Zhou GL, Fung WK.Pan DD, et al. Among authors: zhou gl, zhou jy.Comput Math Methods Med. 2013;2013:843563. doi: 10.1155/2013/843563. Epub 2013 Aug 12.Comput Math Methods Med. 2013.PMID: 24288575Free PMC article.