CHEUNG, K.-W., M. T.-Y. SETO, T.-C. PUN, and K.-Y. TSE. “Vaginal Progesterone to Prevent Preterm Delivery in Unselected Women With Twin Pregnancy: A Randomised, Placebo-Controlled, Double-Blind Trial”. Hong Kong Journal of Gynaecology, Obstetrics and Midwifery, vol. 18, no. 2, Apr. 2023, doi:10.12809/hkjgom.18.2.248.