1. Bennet, G. K., Seashore, H. G., &Wesman, A. G. (1959).Differential aptitude test manual (3rd ed). New York: Psychological Corp.
2. Betts, G. H. (1909).The distribution and functions of mental imagery. New York: Teachers College, Columbia University
3. Epstein, M. L. (1980) The relationship of mental imagery and mental rehearsal to performance of a motor task.Journal of Sport Psychology,2, 211–220.
4. Ernesl, C. H. (1977) Imagery and cognition: A critical revtew.Journal of Mental Imagery,2, 181–216
5. Gordon, R. (1949). An investigation into some of the factors that favour the formation of stereotyped images.British Journal of Psychology,40, 156–157.