TY  - RPRT
TI  - Comparing sample size formulae for trials with unbalanced allocation using the logrank test.
AU  - F Y Hsieh
PY  - 1992
DO  - 10.1002/sim.4780110810
UR  - https://pubmed.ncbi.nlm.nih.gov/1496196/
ID  - 1496196
ER  -