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.
Cha SK, Kim BY, Kim MK, Kim YS, Lee WS, Yoon TK, Lee DR.Cha SK, et al. Among authors: yoon tk.Clin Exp Reprod Med. 2011 Mar;38(1):24-30. doi: 10.5653/cerm.2011.38.1.24. Epub 2011 Mar 31.Clin Exp Reprod Med. 2011.PMID: 22384414Free PMC article.