Djikstra, S., Seel, N., Schott, F. and Tennyson, R. (1997) Instructional Design: International Perspectives, Vols. 1 and 2 Mahwah, NL: Lawrence Erlbaum Associates
Djikstra, S., Seel, N., Schott, F. and Tennyson, R. (1997) Instructional Design: International Perspectives, Vols. 1 and 2 Mahwah, NL: Lawrence Erlbaum Associates