TY - JOUR T1 - Instructional design and the authoring of multimedia and hypermedia systems: Does a marriage make sense? JF - Educational Technology Y1 - 1997 A1 - Gros, Begonia A1 - Elen, Jan A1 - Michael Kerres A1 - Merriënboer, Jeroen A1 - Spector, Michael PB - Universität St. Gallen VL - 37 ER -