DISCLAIMER "This material is provided by the Epidemiology Program Office, which is a sub-unit of CDC/ATSDR. It has been cleared for public distribution by CDC/ATSDR and will be authentic if gotten from ftp.cdc.gov, /pub/epi/epiinfo, pub/epi/epimap or pub/epi/sss." Please see the manuals for Epi Info, Epi Map and SSS for additional information on responsibility and free distribution. Pages 1 and 2 in each manual are particularly relevant.