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.
Normand E, Ban SD, Boesch C.Normand E, et al. Among authors: boesch c.Anim Cogn. 2009 Nov;12(6):797-807. doi: 10.1007/s10071-009-0239-7. Epub 2009 May 31.Anim Cogn. 2009.PMID: 19484488Free PMC article.