To cite PtProcess in publications use:

Harte DS (2010). “PtProcess: An R Package for Modelling Marked Point Processes Indexed by Time.” Journal of Statistical Software, 35(8), 1–32. doi:10.18637/jss.v035.i08, https://cran.r-project.org/package=PtProcess.

Corresponding BibTeX entry:

  @Article{,
    title = {{PtProcess}: An {R} Package for Modelling Marked Point
      Processes Indexed by Time},
    author = {David S. Harte},
    journal = {Journal of Statistical Software},
    year = {2010},
    volume = {35},
    number = {8},
    pages = {1--32},
    doi = {10.18637/jss.v035.i08},
    url = {https://cran.r-project.org/package=PtProcess},
  }