To cite package ‘trust’ in publications use:

  Geyer CJ (2026). _trust: Trust Region Optimization_. R package
  version 0.1-9, <https://CRAN.R-project.org/package=trust>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {trust: Trust Region Optimization},
    author = {Charles J. Geyer},
    year = {2026},
    note = {R package version 0.1-9},
    url = {https://CRAN.R-project.org/package=trust},
  }