To cite package ‘gcapc’ in publications use:

  Teng M, Irizarry RA (2017). Accounting for GC-content bias reduces
  systematic errors and batch effects in ChIP-Seq data.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Accounting for GC-content bias reduces systematic errors and batch effects in ChIP-Seq data.},
    author = {Mingxiang Teng and Rafael A. Irizarry},
    journal = {Genome Research},
    doi = {10.1101/gr.220673.117},
    year = {2017},
  }