  This document is the Part III of the book 'Stochastic Epidemic Models with
Inference' edited by Tom Britton and Etienne Pardoux. Plan of the chapter: 1)
Random Graphs, 2) The Reproduction Number R0, 3) SIR Epidemics on Configuration
Model Graphs, 4) Statistical Description of Epidemics Spreading on Networks:
The Case of Cuban HIV.
