Hamid, A. et al. 2023. Effectiveness Nursing Intervention of Progressive Muscle Relaxation (PMR) on the Fatigue Level of the Older Adults Covid 19 Survivors at Pekanbaru. Jurnal kesehatan komunitas (Journal of community health). 9, 2 (Jul. 2023), 313–319. DOI:https://doi.org/10.25311/keskom.Vol9.Iss2.1340.