TY  - RPRT
TI  - Optimal sampling ratios for prospective studies.
AU  - T Yanagawa
AU  - W J Blot
PY  - 1977
DO  - 10.1093/oxfordjournals.aje.a112487
UR  - https://pubmed.ncbi.nlm.nih.gov/920730/
ID  - 920730
ER  -