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.
Figure 1. From: Social development of children with mental retardation.
CitationFull text
Filter your results:
Your browsing activity is empty.
Activity recording is turned off.
Turn recording back on