To cite package ‘vntrs’ in publications use:

  Oelschläger L (2026). _vntrs: Variable Neighborhood Trust Region
  Search_. R package version 0.2.1,
  <https://CRAN.R-project.org/package=vntrs>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {vntrs: Variable Neighborhood Trust Region Search},
    author = {Lennart Oelschläger},
    year = {2026},
    note = {R package version 0.2.1},
    url = {https://CRAN.R-project.org/package=vntrs},
  }