To cite package 'fungible' in publications use:

Waller, N. G. (2019). fungible: Psychometric Functions from the Waller Lab. R package version 1.86.

Corresponding BibTeX entry:

  @Manual{,
    title = {fungible: Psychometric Functions from the Waller Lab.},
    author = {Niels G. Waller},
    year = {2019},
    note = {version 1.86},
  }