Ulfa, R. M. (2021) “Effect of the Use of Birth Balls on the Reduction of Pain and Duration of Labor During the First Stage of Active and Second Stage of Labor in Primigravida Maternity”, Science Midwifery, 9(2), pp. 418–430. Available at: https://midwifery.iocspublisher.org/index.php/midwifery/article/view/122 (Accessed: 15 September 2026).