Conception and Realization of the Offline Navigator in the Virtual University. - Thomas Demuth; Andreas Rieke; Dagmar Sommer (Teleteaching, 1998)

Experiences in On-Line Tutoring of Multimedia Courses in Distance Education. - Firoz Kaderali; Oda Sans; Sonja Schaup; Dagmar Sommer (Teleteaching, 1998)

Bezahlen in der Virtuellen Universität. - Firoz Kaderali; Biljana Cubaleska; Oda Sans; Dagmar Sommer (D-CSCL, 2000)