TY  - RPRT
TI  - Sequential analysis of spontaneous abortion. II. Collaborative study data show that gravidity determines a very substantial rise in risk.
AU  - A F Naylor
AU  - D Warburton
PY  - 1979
UR  - https://pubmed.ncbi.nlm.nih.gov/437160/
ID  - 437160
ER  -