1. LOGIN: a logic programming language with built-in inheritance;Aït-Kaçi;J. Logic Program.,1986
2. Types, modules and databases in the logic programming language PROTOS-L;Beierle,1990
3. The knowledge representation language LLILOG;Beierle,1989
4. An order-sorted predicate logic with closely coupled taxonomic information;Beierle,1989
5. An algebraic characterization of STUF;Beierle,1988