To cite RGtk2 in publications use:

Lawrence M, Temple Lang D (2010). “RGtk2: A Graphical User Interface Toolkit for R.” Journal of Statistical Software, 37(8), 1–52. http://www.jstatsoft.org/v37/i08/.

Corresponding BibTeX entry:

  @Article{,
    title = {{RGtk2}: A Graphical User Interface Toolkit for {R}},
    author = {Michael Lawrence and Duncan {Temple Lang}},
    journal = {Journal of Statistical Software},
    year = {2010},
    volume = {37},
    number = {8},
    pages = {1--52},
    url = {http://www.jstatsoft.org/v37/i08/},
  }