Rainer Schmidt Lothar Gierl Predicting Influenza Waves with Health Insurance Data. 91-98 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2868&spage=91 2003 conf/ismda/2003 ISMDA db/conf/ismda/ismda2003.html#SchmidtG03