Please cite the multfisher package by the following reference (open access):

Robin Ristl, Dong Xi, Ekkehard Glimm and Martin Posch (2018). Optimal exact tests for multiple binary endpoints. Computational Statistics and Data Analysis 122, 1--17.

Corresponding BibTeX entry:

  @Article{,
    title = {Optimal exact tests for multiple binary endpoints},
    author = {Robin Ristl and Dong Xi and Ekkehard Glimm and Martin
      Posch},
    journal = {Computational Statistics and Data Analysis},
    year = {2018},
    volume = {122},
    pages = {1--17},
  }