To cite package ‘subplex’ in publications use:

King AA, Rowan T (2024). subplex: Unconstrained Optimization using the Subplex Algorithm. R package version 1.9, https://CRAN.R-project.org/package=subplex.

Corresponding BibTeX entry:

  @Manual{,
    title = {subplex: Unconstrained Optimization using the Subplex
      Algorithm},
    author = {Aaron A. King and Tom Rowan},
    year = {2024},
    note = {R package version 1.9},
    url = {https://CRAN.R-project.org/package=subplex},
  }