To cite package ‘ssfa’ in publications use:

Fusco E, Vidoli F (2025). ssfa: Spatial Stochastic Frontier Analysis. R package version 1.2.3, https://CRAN.R-project.org/package=ssfa.

Corresponding BibTeX entry:

  @Manual{,
    title = {ssfa: Spatial Stochastic Frontier Analysis},
    author = {Elisa Fusco and Francesco Vidoli},
    year = {2025},
    note = {R package version 1.2.3},
    url = {https://CRAN.R-project.org/package=ssfa},
  }