To cite package ‘YPBP’ in publications use:

  Demarqui FN (2020). _Yang and Prentice Model with Baseline
  Distribution Modeled by Bernstein Polynomials_. R package version
  0.0.1, <https://CRAN.R-project.org/package=YPBP>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Yang and Prentice Model with Baseline Distribution Modeled by Bernstein Polynomials},
    author = {Fábio N. Demarqui},
    year = {2020},
    note = {R package version 0.0.1},
    url = {https://CRAN.R-project.org/package=YPBP},
  }