Functional Dependencies and Disjunctive Existence Constraints in Database Relations with Null Values. - Paolo Atzeni; Nicola M. Morfuni (ICALP, 1984)

Functional Dependencies in Relations with Null Values. - Paolo Atzeni; Nicola M. Morfuni (Inf. Process. Lett., 1984)

Functional Dependencies and Constraints on Null Values in Database Relations - Paolo Atzeni; Nicola M. Morfuni (Inf. Control., 1986)