1Mayer, R. E. (2003). Learning and instruction. New Jersey: Merrill Prentice Hall. p. 335.
2Mayer, R. E. (2003). Learning and instruction. New Jersey: Merrill Prentice Hall. pp. 467 - 468.
3Atkinson, R. K. et al. (2000). Learning from examples: instructional principles from the worked examples research. Review of Educational Research, Vol. 72, No. 2.
4Mayer, R. E. (2003). Learning and instruction. New Jersey: Merrill Prentice Hall. p. 354.
5Mayer, R. E. (2003). Learning and instruction. New Jersey: Merrill Prentice Hall. p. 343.
