Shumaila Yasin, Sarfraz Ahmed, Mariya Shahbaz, Sabeena Umer, Shazia Roman, Faiza Irshad. Trisomy 21 Testing in Second Trimester: Reliability Comparison of Triple and Quadruple Testing in Pakistan. Pakistan Journal of Medical & Health Sciences [Internet]. 2023 Apr. 30 [cited 2024 Sep. 19];17(03):492. Available from: https://mail.pjmhsonline.com/index.php/pjmhs/article/view/4544