Cite

    Kaspar Rufibach et al.. “Sequentially updating the likelihood of success of a Phase 3 pivotal time-to-event trial based on interim analyses or external information.” Journal of biopharmaceutical statistics, vol. 26, no. 2, 2016, pp. 191–201. http://access.bl.uk/ark:/81055/vdc_100033807296.0x000038