To cite the googleVis package in publications use:

Markus Gesmann and Diego de Castillo. Using the Google Visualisation API with R. The R Journal, 3(2):40-44, December 2011.

Corresponding BibTeX entry:

  @Article{,
    title = {googleVis: Interface between R and the Google
      Visualisation API},
    author = {Markus Gesmann and Diego de Castillo},
    journal = {The R Journal},
    year = {2011},
    volume = {3},
    number = {2},
    pages = {40--44},
    month = {December},
    url =
      {http://journal.r-project.org/archive/2011-2/RJournal_2011-2_Gesmann+de~Castillo.pdf},
  }