To cite the pdfCluster package in publications use:

Azzalini, A. and Menardi, G. (2013). R package 'pdfCluster': Cluster analysis via nonparametric density estimation (Version 1.0-1). With contribution of T. Rosolin up to version 0.0-13. URL http://cran.r-project.org/web/packages/pdfCluster/index.html

Corresponding BibTeX entry:

  @Manual{,
    title = {{R} package \texttt{pdfCluster}: Cluster analysis via
      nonparametric density estimation (Version 1.0-1)},
    author = {A. Azzalini and G. Menardi},
    note = {with contribution of T. Rosolin up to version 0.0-13},
    year = {2013},
    url =
      {http://cran.r-project.org/web/packages/pdfCluster/index.html},
  }