TY  - RPRT
TI  - Toward the optimal protocol for Down syndrome screening.
AU  - J N Macri
AU  - K Spencer
PY  - 1996
DO  - 10.1016/s0002-9378(96)70638-5
UR  - https://pubmed.ncbi.nlm.nih.gov/9065159/
ID  - 9065159
ER  -