To cite package sQuote(gvcm.cat) in publications use:

Margret-Ruth Oelker and the R Development Core Team (2013). gvcm.cat: Regularized Categorial Effects/Categorial Effect Modifiers in GLMs. R package version 1.5.

Corresponding BibTeX entry:

  @Manual{,
    title = {gvcm.cat: Regularized Categorial Effects/Categorial Effect
      Modifiers in GLMs},
    author = {Margret-Ruth Oelker and {R Development Core Team}},
    year = {2013},
    note = {R package version 1.5},
  }