Baader, Franz, Buchheit, Martin and Hollunder, Bernhard. 1996. “Cardinality Restrictions on Concepts.”Artificial Intelligence 88(1–2): 195–213.
Buchheit, Martin, Donini, Francesco M., Nutt, Werner and Schaerf, Andrea. 1998. “A Refined Architecture for Terminological Systems: Terminology \(=\) Schema \(+\) Views.”Artificial Intelligence 99(2): 209–260.