TY  - RPRT
TI  - Maternal age and placenta previa: a population-based, case-control study.
AU  - J Zhang
AU  - D A Savitz
PY  - 1993
DO  - 10.1016/0002-9378(93)90511-g
UR  - https://pubmed.ncbi.nlm.nih.gov/8438945/
ID  - 8438945
ER  -