Approaches to Adding Persistence to Java by Roberto Zicari · Published January 1, 1996 · Updated February 19, 2014 Eliot Moss, Antony Hosking LINK (PDF)
The Object-Relational Impedance Mismatch January 1, 2002 by Roberto Zicari · Published January 1, 2002 · Last modified February 18, 2014
Magic Quadrant for Operational Database Management Systems October 21, 2014 by Roberto Zicari · Published October 21, 2014