To cite 'oposSOM' in publications use:

  Loeffler-Wirth H, Kalcher M, Binder H: oposSOM: R-package for
  high-dimensional portraying of genome-wide expression landscapes on
  Bioconductor.Bioinformatics 2015.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {oposSOM: R-package for high-dimensional portraying of genome-wide expression landscapes on Bioconductor.},
    author = {Henry Loeffler-Wirth and Martin Kalcher and Hans Binder},
    journal = {Bioinformatics},
    year = {2015},
  }