To cite package ‘specL’ in publications use:

  Panse C, Trachsel C, Grossmann J, Schlapbach R (2015). “specL - An
  R/Bioconductor package to prepare peptide spectrum matches for use in
  targeted proteomics.” _Bioinformatics_, 2228-2231.
  DOI:10.1093/bioinformatics/btv105, PMID: 25712692,
  <http://dx.doi.org/10.1093/bioinformatics/btv105>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{spec{L} - {A}n {R}/{B}ioconductor package to prepare peptide spectrum matches for use in targeted proteomics}},
    author = {Christian Panse and Christian Trachsel and Jonas Grossmann and Ralph Schlapbach},
    journal = {Bioinformatics},
    pages = {2228-2231},
    month = {Feb},
    year = {2015},
    note = {DOI:10.1093/bioinformatics/btv105, PMID: 25712692},
    url = {http://dx.doi.org/10.1093/bioinformatics/btv105},
  }