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.
Kopittke PM, Asher CJ, Blamey FP, Menzies NW.Kopittke PM, et al. Among authors: asher cj.Sci Total Environ. 2009 Aug 1;407(16):4616-21. doi: 10.1016/j.scitotenv.2009.04.041. Epub 2009 May 20.Sci Total Environ. 2009.PMID: 19467695
Diatloff E, Smith FW, Asher CJ.Diatloff E, et al. Among authors: asher cj.Ann Bot. 2008 May;101(7):971-82. doi: 10.1093/aob/mcn021. Epub 2008 Feb 21.Ann Bot. 2008.PMID: 18292604Free PMC article.