O-Prasertsawat, P., S. Sapmadee, S. Suthutvoravut, and K. Chaturachinda. “Relationship Between Time of Birth and Perinatal Death Ramathibodi Hospital : 1981 - 1989”. Thai Journal of Obstetrics and Gynaecology, vol. 4, no. 2, July 1992, pp. 85-88, https://he02.tci-thaijo.org/index.php/tjog/article/view/257828.