The Hybrid Object-Relational Architecture (HORA): An Integration of Object-Oriented and Relational Technology. - Jeff Sutherland; Matthew Pope; Ken Rugg (SAC, 1993)

Objects and databases: state of the union in 2006. - William R. Cook; Robert Greene; Patrick Linskey; Erik Meijer 001; Ken Rugg; Craig Russell; Bob Walker; Christof Wittig (OOPSLA Companion, 2006)