src/library/grid/vignettes/grid.bib

@Article{murrell:1999,
  author = 	 {Paul R. Murrell},
  title = 	 {Layouts:  A mechanism for arranging plots on a page},
  journal = 	 {Journal of Computational and Graphical Statistics},
  year = 	 1999,
  volume =       8,
  pages =        {121--134}
}