To cite the 'sn' package in publications use:

Azzalini, A. (2016). The R package 'sn': The Skew-Normal and Skew-t distributions (version 1.4-0). URL http://azzalini.stat.unipd.it/SN

Corresponding BibTeX entry:

  @Manual{,
    title = {The {R} package \texttt{sn}: The Skew-Normal and Skew-$t$
      distributions (version 1.4-0)},
    author = {A. Azzalini},
    address = {Universit\`a di Padova, Italia},
    year = {2016},
    url = {http://azzalini.stat.unipd.it/SN},
  }