To cite package 'agop' in publications use:

Gagolewski M., Cena A. (2014). agop: Aggregation Operators package for R. http://agop.rexamine.com/.

Corresponding BibTeX entry:

  @Manual{,
    title = {agop: Aggregation Operators package for R},
    author = {Marek Gagolewski and Anna Cena},
    year = {2014},
    url = {http://agop.rexamine.com/},
  }