Object Oriented Application Flow Graphs and their Semantics. - Erik de Haas; Peter van Emde Boas (MFCS, 1993)

A Note on Categories of Information Systems. - Jacek Pomykala; Erik de Haas (RSKD, 1993)

Categorial Graphs (Extended Abstract). - Erik de Haas (FCT, 1995)

A Note on Categories of Information Systems. - Janusz Romykala; Erik de Haas (Fundam. Informaticae, 1996)

Grammar Induction as Substructural Inductive Logic Programming. - Pieter W. Adriaans; Erik de Haas (Learning Language in Logic, 1999)

Learning from a Substructural Perspective. - Pieter W. Adriaans; Erik de Haas (CoNLL/LLL, 2000)