To cite package 'fungible' in publications use:

Waller NG (2019). fungible: Psychometric Functions from the Waller Lab.. version 1.91.

Corresponding BibTeX entry:

  @Manual{,
    title = {fungible: Psychometric Functions from the Waller Lab.},
    author = {Niels G. Waller},
    year = {2019},
    note = {version 1.91},
  }