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.
Parry KM.Parry KM.Br Med J (Clin Res Ed). 1981 Jan 3;282(6257):52-5. doi: 10.1136/bmj.282.6257.52.Br Med J (Clin Res Ed). 1981.PMID: 6778568Free PMC article.No abstract available.