The Effect of Tibetan Singing Bowls on Stress Reduction: A Heart Rate Variability Study by Nasrat, Sara A., Alskafi, Feryal A., Ahmad, Dalya Y., Alameri, Raghad O., Albadawna, Haya A., Aldosari, Asmaa J., Alkhanbouli, Ali M., Alkindi, Meirah S., Alzaabi, Shamma S., Jelinek, Herbert F.