To cite RRF in publications use:

Izmirlian G (2004). “Interim Analysis Planning using the PwrGSD package.” NCI Div. of Cancer Prevention.

Izmirlian G (2014). “Estimation of the relative risk following group sequential procedure based upon the weighted log-rank statistic.” Statistics and its Interface, 7(1), 27-42.

Corresponding BibTeX entries:

  @TechReport{,
    title = {Interim Analysis Planning using the PwrGSD package},
    author = {Grant Izmirlian},
    institution = {NCI Div. of Cancer Prevention},
    year = {2004},
  }

  @Article{,
    title = {Estimation of the relative risk following group sequential
      procedure based upon the weighted log-rank statistic},
    author = {Grant Izmirlian},
    journal = {Statistics and its Interface},
    year = {2014},
    volume = {7},
    number = {1},
    pages = {27-42},
  }