To cite GenSA in publications use:

Yang Xiang, Sylvain Gubian, Brian Suomela, Julia Hoeng. Generalized Simulated Annealing for Global Optimization: the GenSA Package. The R Journal, Volume 5(1):13-29, June 2013. URL http://journal.r-project.org/archive/2013-1/xiang-gubian-suomela-etal.pdf

Corresponding BibTeX entry:

  @Article{,
    title = {Generalized Simulated Annealing for Global Optimization:
      the {GenSA} Package.},
    author = {{Yang Xiang} and Sylvain Gubian and Brian Suomela and
      Julia Hoeng},
    journal = {The R Journal Volume 5(1):13-29, June 2013},
    year = {2013},
    url =
      {http://journal.r-project.org/archive/2013-1/xiang-gubian-suomela-etal.pdf},
  }