Franco Barbanera Mariangiola Dezani-Ciancaglini Ivano Salvo Vladimiro Sassone A Type Inference Algorithm for Secure Ambients. 2001 62 Electr. Notes Theor. Comput. Sci. http://dx.doi.org/10.1016/S1571-0661(04)00321-4 db/journals/entcs/entcs62.html#BarbaneraDSS01 83-101