John R. Campbell An Interim Report on the Development of Secure Database Prototypes at the National Computer Security Center. [Citation Graph (0, 0)][DBLP] DBSec, 1989, pp:191-197 [Conf]
John R. Campbell A Research and Development Program for Trusted Distributed Database Systems. [Citation Graph (0, 0)][DBLP] DBSec, 1990, pp:381-394 [Conf]