1. The systematic design of instruction;Dick,1990
2. The conditions of learning and theory of instruction;Gagné,1985
3. Designing effective instruction;Kemp,1994
4. McManus, T. F. (1996). Delivering instruction on the world wide web: hypermedia design model. Available: http://www.svsu.edu/~mcmanus/papers/wbi.html#cognitive [October, 1999]
5. Distance education: a systems view;Moore,1996