To cite drake in publications use:

  William Michael Landau, (2018). The drake R package: a pipeline
  toolkit for reproducibility and high-performance computing. Journal
  of Open Source Software, 3(21), 550,
  https://doi.org/10.21105/joss.00550

A BibTeX entry for LaTeX users is

  @Article{,
    title = {The drake R package: a pipeline toolkit for reproducibility and high-performance computing},
    author = {William Michael Landau},
    journal = {Journal of Open Source Software},
    year = {2018},
    volume = {3},
    number = {21},
    url = {https://doi.org/10.21105/joss.00550},
  }