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.
Kalula SZ, Ferreira M, Thomas KG, de Villiers L, Joska JA, Geffen LN.Kalula SZ, et al. Among authors: ferreira m.S Afr Med J. 2010 Jul 5;100(7):449-51. doi: 10.7196/samj.3384.S Afr Med J. 2010.PMID: 20822593
Kalula SZ, de Villiers L, Ross K, Ferreira M.Kalula SZ, et al. Among authors: ferreira m.S Afr Med J. 2006 Aug;96(8):718-21.S Afr Med J. 2006.PMID: 17019495
de Villiers L, Badri M, Ferreira M, Bryer A.de Villiers L, et al. Among authors: ferreira m.S Afr Med J. 2011 May;101(5):345-8. doi: 10.7196/samj.4588.S Afr Med J. 2011.PMID: 21837880
Kalula SZ, Ferreira M, Swingler GH, Badri M, Sayer AA.Kalula SZ, et al. Among authors: ferreira m.Afr Health Sci. 2017 Sep;17(3):912-922. doi: 10.4314/ahs.v17i3.35.Afr Health Sci. 2017.PMID: 29085420Free PMC article.