To cite package ‘YPmodelPhreg’ in publications use:

  Pak D, Yang S (2023). _YPmodelPhreg: The Short-Term and Long-Term
  Hazard Ratio Model with Proportional Adjustment_. R package version
  1.0.0, <https://CRAN.R-project.org/package=YPmodelPhreg>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {YPmodelPhreg: The Short-Term and Long-Term Hazard Ratio Model with
Proportional Adjustment},
    author = {Daewoo Pak and Song Yang},
    year = {2023},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=YPmodelPhreg},
  }