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.
Wing YK, Zhang J, Ho CK, Au CT, Li AM.Wing YK, et al. Among authors: zhang j.Sleep. 2010 Jun;33(6):759-65. doi: 10.1093/sleep/33.6.759.Sleep. 2010.PMID: 20550016Free PMC article.
Zhang J, Lam SP, Li SX, Li AM, Lai KY, Wing YK.Zhang J, et al.Sleep. 2011 Oct 1;34(10):1395-402. doi: 10.5665/SLEEP.1286.Sleep. 2011.PMID: 21966071Free PMC article.