TY  - RPRT
TI  - First-trimester Down syndrome screening.
AU  - J N Macri
AU  - F Orlandi
PY  - 2000
DO  - 10.1067/mob.2000.109731
UR  - https://pubmed.ncbi.nlm.nih.gov/11120540/
ID  - 11120540
ER  -