TY  - RPRT
TI  - A computer program for designing clinical trials with arbitrary survival curves and group sequential testing.
AU  - J Halpern
AU  - B W Brown
PY  - 1993
DO  - 10.1016/0197-2456(93)90014-5
UR  - https://pubmed.ncbi.nlm.nih.gov/8500301/
ID  - 8500301
ER  -