To cite package ‘combi’ in publications use:

  Hawinkel S, Bijnens L, Lê Cao K, Thas O, R Core Team (????). _combi:
  Integrate omics data for visualization, with special focus on
  compositionality_. R package version 1.17.0.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {{combi}: Integrate omics data for visualization, with special focus on compositionality},
    author = {Stijn Hawinkel and Luc Bijnens and Kim-Anh {L\^e Cao} and Olivier Thas and {R Core Team}},
    note = {R package version 1.17.0},
  }