Tambunan, T. F. U., E. Nathania, and E. P. Tifany. “Application of Daily Step Count in Chronic Obstructive Pulmonary Disease Patient”. Journal Of The Indonesian Medical Association, Vol. 73, no. 5, Dec. 2023, pp. 254 -60, doi:10.47830/jinma-vol.73.5-2023-1054.