Iles, R.K. et al. 2019. The importance of gestational age in first trimester, maternal urine MALDI-Tof MS screening tests for Down Syndrome. Annals of Proteomics and Bioinformatics. 3, 1 (Dec. 2019), 010–017. DOI:https://doi.org/10.29328/journal.apb.1001008.