To cite package ‘flexFitR’ in publications use:

  Aparicio J, Endelman J (2026). _flexFitR: Flexible Non-Linear Least
  Square Model Fitting_. R package version 1.2.3,
  <https://CRAN.R-project.org/package=flexFitR>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {flexFitR: Flexible Non-Linear Least Square Model Fitting},
    author = {Johan Aparicio and Jeffrey Endelman},
    year = {2026},
    note = {R package version 1.2.3},
    url = {https://CRAN.R-project.org/package=flexFitR},
  }