SariS., PandianganT., HarahapJ., and YantiY. “COMBINATION OF BABY EXERCISE AND CLASSICAL MUSIC TOWARDS SLEEP DURATION OF 3 MONTHS BABIES”. JURNAL IBU DAN ANAK, Vol. 9, no. 2, Jan. 2022, pp. 70-74, doi:10.36929/jia.v9i2.395.