To cite ibr in publications use:

Cornillon P, Hengartner N, Matzner-Løber E (2017). “Iterative Bias Reduction Multivariate Smoothing in R: The ibr Package.” Journal of Statistical Software, 77(9), 1–26. doi:10.18637/jss.v077.i09.

Corresponding BibTeX entry:

  @Article{,
    title = {Iterative Bias Reduction Multivariate Smoothing in {R}:
      The {ibr} Package},
    author = {Pierre-Andr\'e Cornillon and Nicolas Hengartner and Eric
      Matzner-L{\o}ber},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {77},
    number = {9},
    pages = {1--26},
    doi = {10.18637/jss.v077.i09},
  }