http://www.helium.com/knowledge/234596-pandemics-and-notable-epidemics-in-the-20th-century.xml Helium.com > Infectious Diseases > Pandemics and notable epidemics in the 20th century en-us Copyright Helium.com Tue, 28 Apr 2009 20:03:43 GMT Tue, 28 Apr 2009 20:03:43 GMT