An Efficient Presentation-Architecture for Personalized Content. - Paul Libbrecht; Carsten Ullrich; Stefan Winterstein (Berliner XML Tage, 2003)

A Flexible and Efficient Presentation-Architecture for Adaptive Hypermedia: Description and Technical Evaluation. - Carsten Ullrich; Paul Libbrecht; Stefan Winterstein; Martin Mühlenbrock (ICALT, 2004)

Semantic-aware components and services of ActiveMath. - Erica Melis; Giorgi Goguadze; Martin Homik; Paul Libbrecht; Carsten Ullrich; Stefan Winterstein (Br. J. Educ. Technol., 2006)

Math-Bridge: Adaptive Platform for Multilingual Mathematics Courses. - Sergey A. Sosnovsky; Michael Dietrich; Eric Andres; George Goguadze; Stefan Winterstein (EC-TEL, 2012)