Vargo F. Gardner, K. R. and Montgomery, P.S. (1977). <i>Clinical Biofeedback: A Procedural Manual.</i>. Can J Couns Psychother [Internet]. 2012 Mar. 26 [cited 2025 Dec. 5];12(4). Available from: https://cjc-rcc.ucalgary.ca/article/view/60204