TY  - RPRT
TI  - Ovulation in relation to cervical canal diameter.
AU  - L B Shettles
PY  - 1988
DO  - 10.1016/0002-9378(88)90607-2
UR  - https://pubmed.ncbi.nlm.nih.gov/3207142/
ID  - 3207142
ER  -