Apirak Nguanboonmak และ Somboon Sornsukolrat. (2019) Prevalence and Risk Factors of Birth Asphyxia amongElderly Gravidarum. <i>Thai Journal of Obstetrics and Gynaecology</i>, <i>27</i>(1), 29-37.Apirak Nguanboonmak และ Somboon Sornsukolrat. "Prevalence and Risk Factors of Birth Asphyxia amongElderly Gravidarum". Thai Journal of Obstetrics and Gynaecology 27 (2019):29-37.Apirak Nguanboonmak และ Somboon Sornsukolrat. Prevalence and Risk Factors of Birth Asphyxia amongElderly Gravidarum. PIMDEE Co. Ltd.:ม.ป.ท. 2019.