Stefano Bistarelli Marco Dall'Aglio Pamela Peretti Strategic Games on Defense Trees. 1-15 2006 conf/ifip1-7/2006 Formal Aspects in Security and Trust http://dx.doi.org/10.1007/978-3-540-75227-1_1 db/conf/ifip1-7/fast2006.html#BistarelliDP06