1. PubMed 2004. Available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi. Accessed June 6, 2004.
2. NaTHNac 2004. Available at: http://www.nathnac.org/. Accessed June 6, 2004.
3. FluNet 2004. Available at: http://oms.b3e.jussieu.fr/flunet/. Accessed June 6, 2004.
4. EWGLI: a European surveillance scheme for travel associated Legionnaires' disease;Hutchinson;Euro Surveill,1996
5. DoDGeis 2004. Available at: http://www.geis.ha.osd.mil/aboutGEIS.asp. Accessed June 6, 2004.