To cite package 'ggbio' in publications use:

  Tengfei Yin, Dianne Cook and Michael Lawrence (2012): ggbio: an R
  package for extending the grammar of graphics for genomic data Genome
  Biology 13:R77

A BibTeX entry for LaTeX users is

  @Article{,
    title = {ggbio: an R package for extending the grammar of graphics for genomic data},
    author = {Tengfei Yin and Dianne Cook and Michael Lawrence},
    journal = {Genome Biology},
    volume = {13},
    number = {8},
    pages = {R77},
    year = {2012},
    publisher = {BioMed Central Ltd},
  }