To cite kohonen in publications use:

Wehrens R, Kruisselbrink J (2018). “Flexible Self-Organizing Maps in kohonen 3.0.” Journal of Statistical Software, 87(7), 1–18. doi:10.18637/jss.v087.i07.

Wehrens R, Buydens LMC (2007). “Self- and Super-Organizing Maps in R: The kohonen Package.” Journal of Statistical Software, 21(5), 1–19. doi:10.18637/jss.v021.i05.

Corresponding BibTeX entries:

  @Article{,
    title = {Flexible Self-Organizing Maps in {kohonen} 3.0},
    author = {Ron Wehrens and Johannes Kruisselbrink},
    journal = {Journal of Statistical Software},
    year = {2018},
    volume = {87},
    number = {7},
    pages = {1--18},
    doi = {10.18637/jss.v087.i07},
  }

  @Article{,
    title = {Self- and Super-Organizing Maps in {R}: The {kohonen}
      Package},
    author = {Ron Wehrens and Lutgarde M. C. Buydens},
    journal = {Journal of Statistical Software},
    year = {2007},
    volume = {21},
    number = {5},
    pages = {1--19},
    doi = {10.18637/jss.v021.i05},
  }