1.
Tongsong T, Sirichotiyakul S. Transvaginal Sonographic Measurements of Crown Rump Length as a Predictor of Gestational Age . Thai J Obstet Gynaecol [internet]. 1993 Jan. 1 [cited 2026 Sep. 28];5(1):1-5. available from: https://he02.tci-thaijo.org/index.php/tjog/article/view/257817