TY  - RPRT
TI  - Confidence intervals following group sequential tests.
AU  - M N Chang
AU  - P C O'Brien
PY  - 1986
DO  - 10.1016/0197-2456(86)90004-8
UR  - https://pubmed.ncbi.nlm.nih.gov/3956209/
ID  - 3956209
ER  -