To cite package ‘protag’ in publications use:

Yuan B (2019). protag: Search Tagged Peptides & Draw Highlighted Mass Spectra. R package version 1.0.0, https://CRAN.R-project.org/package=protag.

Corresponding BibTeX entry:

  @Manual{,
    title = {protag: Search Tagged Peptides & Draw Highlighted Mass
      Spectra},
    author = {Bo Yuan},
    year = {2019},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=protag},
  }