Francesco M. Donini Maurizio Lenzerini Daniele Nardi Werner Nutt Andrea Schaerf Queries, Rules and Definitions as Epistemic Sentences in Concept Languages. 113-132 1992 conf/ecai/1992w1 ECAI Workshop on Knowledge Representation and Reasoning db/conf/ecai/ecai1992w1.html#DoniniLNNS92