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.
Levitin DJ, Tirovolas AK.Levitin DJ, et al.Ann N Y Acad Sci. 2009 Mar;1156:211-31. doi: 10.1111/j.1749-6632.2009.04417.x.Ann N Y Acad Sci. 2009.PMID: 19338510Review.
Levitin DJ, Chordia P, Menon V.Levitin DJ, et al.Proc Natl Acad Sci U S A. 2012 Mar 6;109(10):3716-20. doi: 10.1073/pnas.1113828109. Epub 2012 Feb 21.Proc Natl Acad Sci U S A. 2012.PMID: 22355125Free PMC article.