Smith, Jonathan C. (2007). "Ch. 3: The Psychology of Relaxation". In Lehrer, Paul M.; Woolfolk, Robert L.; Sime, Wesley E. (eds.). Principles and Practice of Stress Management (3rd ed.). Guilford Press. p. 38. ISBN9781606238288.
Smith, Jonathan C. (2007). "Ch. 3: The Psychology of Relaxation". In Lehrer, Paul M.; Woolfolk, Robert L.; Sime, Wesley E. (eds.). Principles and Practice of Stress Management (3rd ed.). Guilford Press. pp. 46–7. ISBN9781606238288.
Rees, Barbara L. (1995). "Effect of Relaxation with Guided Imagery on Anxiety, Depression, and Self-Esteem in Primiparas". Journal of Holistic Nursing. 13 (3): 255–267. doi:10.1177/089801019501300307. PMID7650352. S2CID29229003.
Goessl, V. C.; Curtiss, J. E.; Hofmann, S. G. (2017). "The effect of heart rate variability biofeedback training on stress and anxiety: A meta-analysis". Psychological Medicine. 47 (15): 2578–2586. doi:10.1017/S0033291717001003. PMID28478782. S2CID4710497.
Rees, Barbara L. (1995). "Effect of Relaxation with Guided Imagery on Anxiety, Depression, and Self-Esteem in Primiparas". Journal of Holistic Nursing. 13 (3): 255–267. doi:10.1177/089801019501300307. PMID7650352. S2CID29229003.
Goessl, V. C.; Curtiss, J. E.; Hofmann, S. G. (2017). "The effect of heart rate variability biofeedback training on stress and anxiety: A meta-analysis". Psychological Medicine. 47 (15): 2578–2586. doi:10.1017/S0033291717001003. PMID28478782. S2CID4710497.
Rees, Barbara L. (1995). "Effect of Relaxation with Guided Imagery on Anxiety, Depression, and Self-Esteem in Primiparas". Journal of Holistic Nursing. 13 (3): 255–267. doi:10.1177/089801019501300307. PMID7650352. S2CID29229003.
Goessl, V. C.; Curtiss, J. E.; Hofmann, S. G. (2017). "The effect of heart rate variability biofeedback training on stress and anxiety: A meta-analysis". Psychological Medicine. 47 (15): 2578–2586. doi:10.1017/S0033291717001003. PMID28478782. S2CID4710497.