http://www.health.state.mn.us/divs/idepc/diseases/tb/factsheets/activeviet.pdf
http://www.mhcs.health.nsw.gov.au/mhcs/publication_pdfs/3450/BHC-3450-VIE.pdf
http://www.health.nsw.gov.au/mhcs/publication_pdfs/6140/DOH-6140-VIE.pdf