To cite sfa in publications use:

David H. Bernstein, Christopher F. Parmeter, Alexander D. Stead (2026). “Stochastic Frontier Analysis: The sfa Package.” Working Paper.

Corresponding BibTeX entry:

  @Article{,
    title = {Stochastic Frontier Analysis: The sfa Package},
    author = {{David H. Bernstein} and {Christopher F. Parmeter} and
      {Alexander D. Stead}},
    journal = {Working Paper},
    year = {2026},
  }