http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4853a1.htm

http://www.cdc.gov/mmwr/PDF/wk/mm4853.pdf

http://www.vaccinationnews.com/dailynews/march2002/summnotdisus1999.htm

Part 3. Historical Summaries of Notifiable Diseases in the United States, 1968--1999