To cite StanHeaders in publications use:

Stan Development Team (2018). StanHeaders: Headers for the {R} interface to {Stan}. http://mc-stan.org/.

Corresponding BibTeX entry:

  @Misc{,
    title = {{StanHeaders}: Headers for the {R} interface to {Stan}},
    author = {{Stan Development Team}},
    note = {R package version 2.18.0},
    year = {2018},
    url = {http://mc-stan.org/},
  }