HAU, Wai-Lei, Siu-Ling TSANG, Winny KWAN, Lorraine Siu-King MAN, Kit-Yee LAM, Lai-Fong HO, Hoi-Yan CHEUNG, Fung-King LAI, Chit-Ying LAI, and WH SIN. “The Use of Birth Ball As a Method of Pain Management in Labour”. Hong Kong Journal of Gynaecology, Obstetrics and Midwifery 12, no. 1 (March 31, 2023). Accessed May 8, 2024. https://hkjgom.org/home/article/view/125.