KWAN, Winny SC, Sze-wing CHAN, and Wan-hon LI. “The Birth Ball Experience: Outcome Evaluation of the Intrapartum Use of Birth Ball”. Hong Kong Journal of Gynaecology, Obstetrics and Midwifery 11, no. 1 (March 31, 2023). Accessed May 4, 2024. https://hkjgom.org/home/article/view/114.