@misc{indiciae5732d2c81019,
  title = {Second-trimester placental changes associated with elevated maternal serum alpha-fetoprotein.},
  author = {E A Perkes and R S Baim and K J Goodman and J N Macri},
  year = {1982},
  doi = {10.1016/0002-9378(82)90188-0},
  url = {https://pubmed.ncbi.nlm.nih.gov/6183975/},
  note = {Source identifier: 6183975}
}