info:oai:pure.iiasa.ac.at:4748info:ofi/fmt:xml:xsd:bookHeesterbeekJ.A.P.Heesterbeek, J.A.P.MetzJ.A.J.Metz, J.A.J.19960-521-45339-9The saturating contact rate in epidemic modelsModels for Infectious Human Diseases: Their Structure and Relation to Databookitem