To cite the vsn package in publications use:

  Wolfgang Huber, Anja von Heydebreck, Holger Sueltmann, Annemarie
  Poustka and Martin Vingron. Variance Stabilization Applied to
  Microarray Data Calibration and to the Quantification of Differential
  Expression. Bioinformatics 18, S96-S104 (2002).

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Variance Stabilization Applied to Microarray Data Calibration and to the Quantification of Differential Expression},
    author = {Wolfgang Huber and Anja {von Heydebreck} and Holger Sueltmann and Annemarie Poustka and Martin Vingron},
    journal = {Bioinformatics},
    year = {2002},
    volume = {18 Suppl. 1},
    pages = {S96-S104},
  }