Arends , J., P. Hyltoft Petersen, and B. Nørgaard-Pedersen. “6.1.2.3 Prenatal Screening for Neural Tube Defects, Quality Specification for Maternal Serum Alphafetoprotein Analysis”. Upsala Journal of Medical Sciences 98, no. 3 (September 1, 1993): 339-347. Accessed March 27, 2026. https://ujms.net/index.php/ujms/article/view/7493.