To cite package ‘limmaGUI’ in publications use:

  Wettenhall, J. M. and Smyth, G. K. (2004). limmaGUI: a graphical user
  interface for linear modeling of microarray data. Bioinformatics 20,
  3705-3706.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{limmaGUI}: a graphical user interface for linear modeling of microarray data},
    author = {Gordon K Smyth and James M Wettenhall},
    journal = {Bioinformatics},
    year = {2004},
    volume = {20},
    pages = {3705-3706},
    year = {2004},
  }