@Manual{R,
  title = {R: A Language and Environment for Statistical Computing},
  author = {{R Core Team}},
  organization = {R Foundation for Statistical Computing},
  address = {Vienna, Austria},
  year = {2012},
  note = {{ISBN} 3-900051-07-0},
  url = {http://www.R-project.org/},
}

@article{ihaka:1996,
  Author = {Ihaka, Ross and Gentleman, Robert},
	Journal = {Journal of Computational and Graphical Statistics},
	Number = 3,
	Pages = {299--314},
	Title = {R: A Language for Data Analysis and Graphics},
	Volume = 5,
	Year = 1996}