Carlson, C. ., FL, C. . , Jr, Nitz, A. ., Sturgis, E. ., & Rogers, J. . (1990). Muscle stretching as an alternative relaxation training procedure. Journal of Behavior Therapy and Experimental Psychiatry, 21(1), 29-38. https://doi.org/10.1016/0005-7916(90)90046-n

FL, C. . , Jr, Baer, R. ., & Blount, R. . (1985). Single-subject research designs for optometry. American Journal of Optometry and Physiological Optics, 62(8), 516-22. https://doi.org/10.1097/00006324-198508000-00004