An object-oriented approach to knowledge representation in a biomedical domain. - Marco Ensing; Ray Paton; Piet-Hein Speel; Roy Rada (Artif. Intell. Medicine, 1994)

Can Description Logics Be Used in Real-Life Knowledge-Based Systems? - Piet-Hein Speel (Description Logics, 1996)

Managing Data and Knowledge in the Industrial Unilever Environment. - Piet-Hein Speel (KRDB, 1996)

Applying a library of problem-solving methods on a real-life task. - Piet-Hein Speel; Manfred Aben (Int. J. Hum. Comput. Stud., 1997)

Preserving conceptual structures in design and implementation of industrial KBS. - Piet-Hein Speel; Manfred Aben (Int. J. Hum. Comput. Stud., 1998)