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.
Piper MC, Lippman-Hand A.Piper MC, et al. Among authors: lippman hand a.J Ment Defic Res. 1981 Sep;25(Pt 3):217-23. doi: 10.1111/j.1365-2788.1981.tb00111.x.J Ment Defic Res. 1981.PMID: 6456357