To cite the psica package in publications use:

Sysoev, O. and Bartoszek, K. and Ekstrom., EC. and Ekholm Selling, K.(2019) PSICA: decision trees for probabilistic subgroup identification with categorical treatments Statistics in Medicine. 2019; 38: 4436-4452

Corresponding BibTeX entry:

  @Article{,
    author = {Oleg Sysoev and Krzysztof Bartoszek and Eva-Charlotta
      Ekstrom and Katarina Ekholm Selling},
    title = {PSICA: decision trees for probabilistic subgroup
      identification with categorical treatments},
    year = {2019},
    volume = {38},
    pages = {4436-4452},
    journal = {Statistics in Medicine},
  }