1. Birren, F. Color psychology and color therapy. New York: University Books, 1961.
2. Calef, R. S., Calef, R. A., Piper, D., Wilson, S. A., & Geller, E. S. Imagined verbal transformations as a function of age and verbal intelligence. Bulletin of the Psychonomic Society, 1977, 10, 109–110.
3. Gerard, R. M. Differential effects of color lights on psychophysiological functions. Unpublished doctoral dissertation. University of California, Los Angeles, 1958.
4. Goldstein, K. Some experimental observations concerning the influence of colors on the functions of the organism. Occupational Therapy, 1942, 21, 147–151.
5. Goodfellow, R. A. H., & Smith, P. C. Effects of environmental color on two psychomotor tasks. Perceptual and Motor Skills, 1973, 37, 296–298.