Using Computer Algebra Systems as Cognitive Tools. - Jochen Büdenbender; Adrian Frischauf; Georgi Goguadze; Erica Melis; Paul Libbrecht; Carsten Ullrich (Intelligent Tutoring Systems, 2002)

Semantics for Web-Based Mathematical Education Systems. - Erica Melis; Jochen Büdenbender; Georgi Goguadze; Paul Libbrecht; Carsten Ullrich (Semantic Web Workshop, 2002)

Knowledge Representation and Management in ACTIVEMATH. - Erica Melis; Jochen Büdenbender; Georgi Goguadze; Paul Libbrecht; Carsten Ullrich (Ann. Math. Artif. Intell., 2003)