To cite package ‘seguid’ in publications use:

  Babnigg, György, and Carol S Giometti, A database of unique protein
  sequence identifiers for proteome studies. Proteomics (2006) 6 (16):
  4514–22. https://doi.org/10.1002/pmic.200600032

A BibTeX entry for LaTeX users is

  @Article{,
    title = {A database of unique protein sequence identifiers for proteome studies},
    author = {Gy{"o}rgy Babnigg and Carol S. Giometti},
    journal = {Proteomics},
    publisher = {Wiley},
    volume = {6},
    number = {16},
    pages = {4514--4522},
    month = {aug},
    year = {2006},
    issn = {1615-9853, 1615-9861},
    pmid = {16858731},
    doi = {10.1002/pmic.200600032},
  }