tunik, tunik, Niningasih, R., & Yuswantoro, E. (2020). The Effectiveness of Breath Relaxation with Balloon Blowing Technique towards Oxygen Saturation of COPD Patients. Jurnal Pendidikan Kesehatan (e-Journal), 9(2), 193–199. https://doi.org/10.31290/jpk.v9i2.2031