8P. Dean, M. Stahl, D. Sylwester, J. Peat. Effectiveness of Combined Delivery Modalities for Distance Learning and Resident Learning. Quarterly Review of Distance Education, July/August 2001.
9The 4-tier Model: Managine the New e-Learning Curve. http://www -3.ibm.com/mindspan/ mindspan.nsf/3b14a881692bc3c085256aed006fb063/2fe3c4e93agb1ffb87256c2700498bbb/$FILE/LSP-2002-022-B.pdf.
10Moore, M. G., & Kearsley, G. (1996). Distance education: Asystems view. Belmont, C A: Wadsworth Publishing Company.
