Yue G. H., Cole K. J. Strength increases from the motor program; comparison of training with maximal voluntary and imagined muscle contractions // Journal of neuropsychology. 1992. № 67. P. 114–123; Ranganathan V. K. et al. Increasing muscle strength by training the central nervous system without physical exercise // Society for neuroscience abstracts. 2001. № 31. P. 17: Ranganathan V. K. et al. Level of mental effort determines training— induced strength increases // Society of neuroscience abstracts. 2002. № 31. P. 768; Cohen P. Mental gymnastics // New Scientist. 2001. November 24. № 172 (2318). P. 17.