To cite rPraat in publications use:

Bořil, T., & Skarnitzl, R. (2016). Tools rPraat and mPraat. In P. Sojka, A. Horák, I. Kopeček, & K. Pala (Eds.), Text, Speech, and Dialogue (pp. 367-374). Springer International Publishing.

Corresponding BibTeX entry:

  @InProceedings{,
    author = {Tomáš Bořil and Radek Skarnitzl},
    editor = {Petr Sojka and Aleš Horák and Ivan Kopeček and Karel
      Pala},
    booktitle = {Text, Speech, and Dialogue: 19th International
      Conference, TSD 2016, Brno, Czech Republic, September 12-16,
      2016, Proceedings},
    publisher = {Springer International Publishing},
    address = {Cham},
    year = {2016},
    title = {Tools rPraat and mPraat},
    pages = {367--374},
    isbn = {978-3-319-45510-5},
    doi = {10.1007/978-3-319-45510-5_42},
    url = {http://dx.doi.org/10.1007/978-3-319-45510-5_42},
  }