Johannsen, G.; Borys, B.-B.; Sundstrцm, G. A.; Fejes, L. & Strдtz, G. (1989), Issues of Design Support and User Modelling for Intelligent Graphical Editors, and Presentation System: ESPRIT-Gradient-P857 Report WP4+11-UKS-055, Vol. MMS-8, Kassel.

Johannsen, G.; Borys, B.-B.; Sundström, G. A.; Fejes, L. & Strätz, G. (1989), Issues of Design Support and User Modelling for Intelligent Graphical Editors, and Presentation System: ESPRIT-Gradient-P857 Report WP4+11-UKS-055, Vol. MMS-8, Kassel.