To cite package 'muRL' in publications use:

Moore, Ryan T. and Andrew Reeves (2017). muRL: Mailmerge using R, LateX, and the Web. R package version 0.1-11.

Corresponding BibTeX entry:

  @Manual{,
    title = {muRL: Mailmerge using R, LateX, and the Web},
    author = {Ryan T. Moore and Andrew Reeves},
    year = {2017},
    note = {R package version 0.1-11},
  }