TY  - RPRT
TI  - Effectiveness and risks of birth-control methods.
AU  - D M Potts
AU  - G I Swyer
PY  - 1970
DO  - 10.1093/oxfordjournals.bmb.a070738
UR  - https://pubmed.ncbi.nlm.nih.gov/4904683/
ID  - 4904683
ER  -