Luca Aceto Silvio Capobianco Anna Ingólfsdóttir Bas Luttik The equational theory of prebisimilarity over basic CCS with divergence. 284-289 2008 108 Inf. Process. Lett. 5 http://dx.doi.org/10.1016/j.ipl.2008.05.019 db/journals/ipl/ipl108.html#AcetoCIL08