To cite package ‘ArCo’ in publications use:

  Fonseca Y, Masini R, Medeiros M, Vasconcelos G (2017). _ArCo:
  Artificial Counterfactual Package_. R package version 0.3-1,
  <https://github.com/gabrielrvsc/arco>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ArCo: Artificial Counterfactual Package},
    author = {Yuri R. Fonseca and Ricardo Masini and Marcelo C. Medeiros and Gabriel F. R. Vasconcelos},
    year = {2017},
    note = {R package version 0.3-1},
    url = {https://github.com/gabrielrvsc/arco},
  }