To cite clickstream in publications use:

Michael Scholz (2016). R Package clickstream: Analyzing Clickstream Data with Markov Chains. Journal of Statistical Software, 74(4), 1-17.<doi:10.18637/jss.v074.i04>

Corresponding BibTeX entry:

  @Article{,
    title = {{R} Package {clickstream}: Analyzing Clickstream Data with
      Markov Chains},
    author = {Michael Scholz},
    journal = {Journal of Statistical Software},
    year = {2016},
    volume = {74},
    number = {4},
    pages = {1--17},
    doi = {10.18637/jss.v074.i04},
  }