TY  - RPRT
TI  - Group sequential methods for cohort and case-control studies.
AU  - B S Pasternak
AU  - R E Shore
PY  - 1980
DO  - 10.1016/0021-9681(80)90046-6
UR  - https://pubmed.ncbi.nlm.nih.gov/7372772/
ID  - 7372772
ER  -