To cite kofnGA in publications use:

Wolters MA (2015). “A Genetic Algorithm for Selection of Fixed-Size Subsets with Application to Design Problems.” Journal of Statistical Software, Code Snippets, 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},
  }