Krampen Günter. “Randomized Controlled Trials on Relaxation Training in Complementary Treatment of Mental Disorders”. Journal of Psychology and Psychotherapy Research 4, no. 1 (February 27, 2017): 9–26. Accessed May 11, 2025. http://www.savvysciencepublishers.com/index.php/jppr/article/view/562.