Sulistyawati, E., A. Allenidekania, and D. Gayatri. “Effect of Progressive Muscle Relaxation on Sleep Quality and Side Effects of Chemotherapy in Children With Cancer: Randomized Clinical Trial”. Open Access Macedonian Journal of Medical Sciences, vol. 9, no. T4, June 2021, pp. 300-8, doi:10.3889/oamjms.2021.5774.