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.
de Klerk A, van Schalkwyk E, Williams Z, Lee W, Bardin P.de Klerk A, et al. Among authors: van schalkwyk e.S Afr Med J. 2002 Feb;92(2):140-4.S Afr Med J. 2002.PMID: 11894651
van der Merwe L, de Klerk A, Kidd M, Bardin PG, van Schalkwyk EM.van der Merwe L, et al. Among authors: van schalkwyk em.Thorax. 2006 Sep;61(9):756-60. doi: 10.1136/thx.2005.052308.Thorax. 2006.PMID: 16936235Free PMC article.
Ferreira A, Williams Z, Donninger H, van Schalkwyk EM, Bardin PG.Ferreira A, et al.Respiration. 2002;69(2):136-42. doi: 10.1159/000056316.Respiration. 2002.PMID: 11961427
Mattheyse FJ, van Heerden K, Mattheyse M, Williams Z, Bouic P, van Schalkwyk EM, Bardin PG.Mattheyse FJ, et al. Among authors: van schalkwyk em, van heerden k.Respiration. 2001;68(5):471-9. doi: 10.1159/000050553.Respiration. 2001.PMID: 11694808
van Schalkwyk EM, Schultz C, Joubert JR, White NW; South African Thoracic Society Standards of Spirometry Committee.van Schalkwyk EM, et al.S Afr Med J. 2004 Jul;94(7 Pt 2):576-87.S Afr Med J. 2004.PMID: 15283308
Esterhuizen TM, Hnizdo E, Rees D, Lalloo UG, Kielkowski D, van Schalkwyk EM, White N, Smith FC, Hoggins B, Curtis T.Esterhuizen TM, et al. Among authors: van schalkwyk em.S Afr Med J. 2001 Jun;91(6):502-8.S Afr Med J. 2001.PMID: 11455715
Wyser C, Walzl G, Smedema JP, Swart F, van Schalkwyk EM, van de Wal BW.Wyser C, et al. Among authors: van schalkwyk em, van de wal bw.Chest. 1996 Aug;110(2):333-8. doi: 10.1378/chest.110.2.333.Chest. 1996.PMID: 8697829Clinical Trial.