Thiraphalawat, R. “Effects of Spontaneous Pushing With Perineal Massage on Pushing Duration, Postpartum Fatigue and Satisfaction in Primiparous Woman”. The Journal of Chulabhorn Royal Academy, vol. 3, no. 3, July 2021, pp. 168-79, https://he02.tci-thaijo.org/index.php/jcra/article/view/250956.