@misc{indiciae901135a63d5a,
  title = {Repeat maternal serum testing for Down's syndrome screening using multiple markers with special reference to free alpha and free beta-hCG.},
  author = {A K Hackshaw and J Densem and N J Wald},
  year = {1995},
  doi = {10.1002/pd.1970151208},
  url = {https://pubmed.ncbi.nlm.nih.gov/8750292/},
  note = {Source identifier: 8750292}
}