To cite the topdownr package in publications use:

P.V. Shliaha, S. Gibb, V. Gorshkov, M.S. Jespersen, G.R. Andersen, D. Bailey, J. Schwartz, S. Eliuk, V. Schwämmle, and O.N. Jensen. 2018. Maximizing Sequence Coverage in Top-Down Proteomics By Automated Multi-modal Gas-phase Protein Fragmentation. Analytical Chemistry.<doi:10.1021/acs.analchem.8b02344>

Corresponding BibTeX entry:

  @Article{topdownr,
    title = {Maximizing Sequence Coverage in Top-Down Proteomics By
      Automated Multi-modal Gas-phase Protein Fragmentation.},
    author = {Pavel Vyacheslavovich Shliaha and Sebastian Gibb and
      Vladimir Gorshkov and Malena Schack Jespersen and Gregers R.
      Andersen and Derek Bailey and Jacob Schwartz and Shannon Eliuk
      and Veit Schwämmle and Ole Nørregaard Jensen},
    volume = {90},
    number = {21},
    pages = {12519--12526},
    year = {2018},
    doi = {10.1021/acs.analchem.8b02344},
    url = {https://pubs.acs.org/doi/10.1021/acs.analchem.8b02344},
    eprint =
      {https://pubs.acs.org/doi/pdf/10.1021/acs.analchem.8b02344},
    journal = {Analytical Chemistry},
    publisher = {American Chemical Society},
  }