To cite package ‘sig’ in publications use:

Cotton R (2016). sig: Print Function Signatures. R package version 0.0-6, https://bitbucket.org/richierocks/sig.

Corresponding BibTeX entry:

  @Manual{,
    title = {sig: Print Function Signatures},
    author = {Richard Cotton},
    year = {2016},
    note = {R package version 0.0-6},
    url = {https://bitbucket.org/richierocks/sig},
  }