Soufiene Benkirane Jane Hillston Chris McCaig Rachel Norman Carron Shankland Improved Continuous Approximation of PEPA Models through Epidemiological Examples. 59-74 2009 229 Electr. Notes Theor. Comput. Sci. 1 http://dx.doi.org/10.1016/j.entcs.2009.02.005 db/journals/entcs/entcs229.html#BenkiraneHMNS09