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.
Heffner JE, Huggins JT.Heffner JE, et al. Among authors: huggins jt.Chest. 2004 Apr;125(4):1190-2. doi: 10.1378/chest.125.4.1190.Chest. 2004.PMID: 15078722No abstract available.