To cite package ‘IgGeneUsage’ in publications use:

  Kitanovski, Simo, and Daniel Hoffmann. IgGeneUsage: differential gene
  usage in immune repertoires. Bioinformatics (2020).

A BibTeX entry for LaTeX users is

  @Article{,
    title = {IgGeneUsage: differential gene usage in immune repertoires},
    author = {Simo Kitanovski and Daniel Hoffmann},
    year = {2020},
    journal = {Bioinformatics},
    doi = {10.1093/bioinformatics/btaa174},
    issue = {-3436},
  }