Kathrin Hoffmann Till Mossakowski Francesco Parisi-Presicce Higher-Order Nets for Mobile Policies. 87-105 2005 127 Electr. Notes Theor. Comput. Sci. 2 http://dx.doi.org/10.1016/j.entcs.2005.02.007 db/journals/entcs/entcs127.html#HoffmannMP05