TY  - RPRT
TI  - Statistical evaluation of the rhythm method.
AU  - C TIETZE
AU  - R G POTTER
PY  - 1962
DO  - 10.1016/0002-9378(62)90166-7
UR  - https://pubmed.ncbi.nlm.nih.gov/13921194/
ID  - 13921194
ER  -