Fitria, R., and R. Wahyuny. “THE EFFECTIVENESS OF GIVING BIRTH BALL METHOD TO THE INTENSITY OF STAGE I LABOR PAIN IN THE ACTIVE PHASE IN BPM ROKAN HULU: EFEKTIVITAS PEMBERIAN METODE BIRTH BALL TERHADAP INTENSITAS NYERI PERSALINAN KALA I FASE AKTIF DI BPM ROKAN HULU”. Jurnal Martenity and Neonatal, vol. 3, no. 3, Feb. 2021, pp. 210-2, https://e-journal.upp.ac.id/index.php/akbd/article/view/2173.