S. Rao Vasireddy Steven Wolter Uma Chandrashekhar Robert J. Thornberry Jr. Andrew R. McGee Security posture for civilian and non-civilian networks. 187-202 2004 8 Bell Labs Technical Journal 4 http://dx.doi.org/10.1002/bltj.10095 db/journals/bell/bell8.html#VasireddyWCTM04