To cite the tcltk2 package:

Ph. Grosjean (2009). tcltk2: additional Tcl/Tk widgets and commands for R. see: http://www.sciviews.org/SciViews-R.

We have invested a lot of time and effort in creating this package. Please, use it for building your R GUIs. See also ‘citation("pkgname")’ for citing other R packages.

Corresponding BibTeX entry:

  @Manual{,
    title = {tcltk2: additional Tcl/Tk widgets and commands for R},
    author = {{Philippe Grosjean}},
    organization = {SciViews},
    address = {Belgium},
    year = {2009},
    url = {http://www.sciviews.org/SciViews-R},
  }