To cite package 'hmmm' in publications use:

Roberto Colombi, Sabrina Giordano, Manuela Cazzaro, and the R Development Core Team (2013). hmmm: Hierarchical Multinomial Marginal Models. R package version 1.0-2.

Corresponding BibTeX entry:

  @Manual{,
    title = {hmmm: Hierarchical Multinomial Marginal Models},
    author = {Roberto Colombi and Sabrina Giordano and Manuela Cazzaro
      and {R Development Core Team}},
    year = {2014},
    note = {R package version 1.0-2},
  }