Question: 1. Ronald Fagin. "On an Authorization Mechanism." ACM PODS 3, No. 3 (September 1978). An extended corrigendum to reference [15.11]. Under certain circumstances the mecha-nism of reference [15.11) would revoke a privilege that ought not to be revoked. This paper corrects that flaw.
2. Eduardo B. Fernandez, Rita C. Summers, and Christopher Wood. Database Security and Integrity. Reading. Mass.: Addison-Wesley (1981).