TY  - RPRT
TI  - Repeat maternal serum testing for Down's syndrome screening using multiple markers with special reference to free alpha and free beta-hCG.
AU  - A K Hackshaw
AU  - J Densem
AU  - N J Wald
PY  - 1995
DO  - 10.1002/pd.1970151208
UR  - https://pubmed.ncbi.nlm.nih.gov/8750292/
ID  - 8750292
ER  -