To cite aspect in publications use:

Patrick Mair, Jan de Leeuw (2010). A General Framework for Multivariate Analysis with Optimal Scaling: The R Package aspect. Journal of Statistical Software, 32(9), 1-23. URL http://www.jstatsoft.org/v32/i09/.

Corresponding BibTeX entry:

  @Article{,
    title = {A General Framework for Multivariate Analysis with Optimal
      Scaling: The {R} Package {aspect}},
    author = {Patrick Mair and Jan de Leeuw},
    journal = {Journal of Statistical Software},
    year = {2010},
    volume = {32},
    number = {9},
    pages = {1--23},
    url = {http://www.jstatsoft.org/v32/i09/},
  }