To cite package 'secrfunc' in publications use:

  Efford, M. G. (2025). secrfunc: Helper Functions for Package 'secr' R
  package version 1.0.0.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {secrfunc: Helper Functions for Package 'secr'},
    author = {Murray Efford},
    year = {2025},
    note = {R package version 1.0.0},
  }