TY  - RPRT
TI  - Coital frequency and twinning.
AU  - B Bønnelykke
AU  - J Olsen
AU  - J Nielsen
PY  - 1990
DO  - 10.1017/s0021932000018526
UR  - https://pubmed.ncbi.nlm.nih.gov/2335540/
ID  - 2335540
ER  -