Astrika, G., Panggayuh, A., & Mardiyanti, T. (2019). The Effect Of Birthing Ball On The Duration Of Active Phase In Primigravida At Pmb Yulis Indriana, Malang. Jurnal Pendidikan Kesehatan (E-Journal), 8(2), 164 - 175. doi:10.31290/jpk.v8i2.1021