To cite package ‘isotone’ in publications use:

  Mair P, De Leeuw J, Hornik K (2023). _isotone: Active Set and
  Generalized PAVA for Isotone Optimization_. R package version 1.1-1,
  <https://r-forge.r-project.org/projects/psychor/>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {isotone: Active Set and Generalized PAVA for Isotone Optimization},
    author = {Patrick Mair and Jan {De Leeuw} and Kurt Hornik},
    year = {2023},
    note = {R package version 1.1-1},
    url = {https://r-forge.r-project.org/projects/psychor/},
  }

  de Leeuw J, Hornik K, mair P (2009). “Isotone Optimization in R:
  Pool-Adjacent-Violators Algorithm (PAVA) and Active Set Methods.”
  _Journal of Statistical Software_, *32*(5), 1-24.
  <https://doi.org/10.18637/jss.v032.i05>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Isotone Optimization in {R}: Pool-Adjacent-Violators Algorithm (PAVA) and Active Set Methods},
    author = {Jan {de Leeuw} and Kurt Hornik and Patrick mair},
    journal = {Journal of Statistical Software},
    year = {2009},
    volume = {32},
    number = {5},
    pages = {1--24},
    url = {https://doi.org/10.18637/jss.v032.i05},
  }