Victor M. Markowitz, Arie Shoshani Representing Extended Entity-Relationship Structures in Relational Databases: A Modular Approach. [Citation Graph (19, 20)][DBLP] ACM Trans. Database Syst., 1992, v:17, n:3, pp:423-464 [Journal]
C. J. Date, Ronald Fagin Simple Conditions for Guaranteeing Higher Normal Forms in Relational Databases. [Citation Graph (1, 9)][DBLP] ACM Trans. Database Syst., 1992, v:17, n:3, pp:465-476 [Journal]