To cite package 'isobar' in publications use:

  Breitwieser FP, Mueller A, Dayon L, Koecher T, Hainard A, Pichler P,
  Schmidt-Erfurth U, Superti-Furga G, Sanchez J, Mechtler K, Bennett KL
  and Colinge J (2011). 'General statistical modeling of data from
  protein relative expression isobaric tags.' _Journal of Proteome
  Research_. <URL: http://bioinformatics.cemm.oeaw.ac.at/isobar>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {General statistical modeling of data from protein relative expression isobaric tags},
    author = {Florian P Breitwieser and Andre Mueller and Loic Dayon and Thomas Koecher and Alexandre Hainard and Peter Pichler and Ursula Schmidt-Erfurth and Giulio Superti-Furga and Jean-Charles Sanchez and Karl Mechtler and Keiryn L Bennett and Jacques Colinge},
    journal = {Journal of Proteome Research},
    institution = {Research Center of Molecular Medicine of the Austrian Academy of Sciences},
    address = {Vienna, Austria},
    year = {2011},
    url = {http://bioinformatics.cemm.oeaw.ac.at/isobar},
  }