To cite package ‘coxphf’ in publications use:

Heinze G, Ploner M, Jiricka L, Steiner G (2023). coxphf: Cox Regression with Firth's Penalized Likelihood. R package version 1.13.4, https://github.com/georgheinze/coxphf.

Corresponding BibTeX entry:

  @Manual{,
    title = {coxphf: Cox Regression with Firth's Penalized Likelihood},
    author = {Georg Heinze and Meinhard Ploner and Lena Jiricka and
      Gregor Steiner},
    year = {2023},
    note = {R package version 1.13.4},
    url = {https://github.com/georgheinze/coxphf},
  }