auk/ publicationstspeeches/2009/speech409pd0 (2009). This ewes a more lull account of the policy issues discussed here. 38. Anderson. R. M. & May. R. Minfectious Diseases of Humans: Transmission and ControtCh12.3 (Oxford Univ. Press. 1991). 39. Barabea.A.L Linked: The New Science of Networks (Perseus, 2002).