To cite smacof in publications use:

de Leeuw J, Mair P (2009). “Multidimensional Scaling Using Majorization: SMACOF in R.” Journal of Statistical Software, 31(3), 1–30. https://doi.org/10.18637/jss.v031.i03.

Mair P, Groenen PJF, de Leeuw J (2022). “More on multidimensional scaling in R: smacof version 2.” Journal of Statistical Software, 102(10), 1–47. https://doi.org/10.18637/jss.v102.i10.

Corresponding BibTeX entries:

  @Article{,
    title = {Multidimensional Scaling Using Majorization: {SMACOF} in
      {R}},
    author = {Jan {de Leeuw} and Patrick Mair},
    journal = {Journal of Statistical Software},
    year = {2009},
    volume = {31},
    number = {3},
    pages = {1--30},
    url = {https://doi.org/10.18637/jss.v031.i03},
  }

  @Article{,
    title = {More on multidimensional scaling in {R}: smacof version
      2},
    author = {Patrick Mair and Patrick J. F. Groenen and Jan {de
      Leeuw}},
    journal = {Journal of Statistical Software},
    year = {2022},
    volume = {102},
    number = {10},
    pages = {1--47},
    url = {https://doi.org/10.18637/jss.v102.i10},
  }