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.
Butz A, Hutton N, Larson E.Butz A, et al.Am J Public Health. 1991 Oct;81(10):1323-6. doi: 10.2105/ajph.81.10.1323.Am J Public Health. 1991.PMID: 1928535Free PMC article.
Gerson AC, Joyner M, Fosarelli P, Butz A, Wissow L, Lee S, Marks P, Hutton N.Gerson AC, et al.J Pediatr Health Care. 2001 Jul-Aug;15(4):161-7. doi: 10.1067/mph.2001.114835.J Pediatr Health Care. 2001.PMID: 11462122Review.