Learner-control and instructional technologies (Williams 1996)
http://www.education.umd.edu/EDHD/faculty2/Azevedo/courses/spring03/edhd779A/Williams(1996).pdf
Cognitive Theory and the Design of Multimedia Instruction:
An Example of Two-Way Street Between Cognition and Instruction
http://www.fp.ucalgary.ca/maclachlan/cognitive_theory_mm_design.pdf
