To cite kofnGA in publications use:

Mark A. Wolters (2015). A Genetic Algorithm for Selection of Fixed-Size Subsets with Application to Design Problems. Journal of Statistical Software, 68(1), 1-18.<doi:10.18637/jss.v068.c01>

Corresponding BibTeX entry:

  @Article{,
    title = {A Genetic Algorithm for Selection of Fixed-Size Subsets
      with Application to Design Problems},
    author = {Mark A. Wolters},
    journal = {Journal of Statistical Software, Code Snippets},
    year = {2015},
    volume = {68},
    number = {1},
    pages = {1--18},
    doi = {10.18637/jss.v068.c01},
  }