To cite package ‘formula.tools’ in publications use:

Brown C (2018). formula.tools: Programmatic Utilities for Manipulating Formulas, Expressions, Calls, Assignments and Other R Objects. R package version 1.7.1, https://github.com/decisionpatterns/formula.tools.

Corresponding BibTeX entry:

  @Manual{,
    title = {formula.tools: Programmatic Utilities for Manipulating
      Formulas, Expressions, Calls, Assignments and Other R Objects},
    author = {Christopher Brown},
    year = {2018},
    note = {R package version 1.7.1},
    url = {https://github.com/decisionpatterns/formula.tools},
  }