TY - JOUR A1 - Unz, Dagmar A1 - Hesse, F.W. T1 - The Use of Hypertext for Learning JF - Journal of Educational Computing Research Y1 - 1999 UR - http://permalink.bibkatalog.de/BV022209386 VL - 20 IS - 3 SP - 279 EP - 295 ER -