Singhal N, Gupta AS. An observational study to determine accuracy of various methods used to assign gestational age and correlate with outcome. Int J Reprod Contracept Obstet Gynecol [Internet]. 2018 Aug. 27 [cited 2025 Dec. 29];7(9):3790-5. Available from: https://www.ijrcog.org/index.php/ijrcog/article/view/5289