To cite the DiffLogo package in publications:

M. Nettling, H. Treutler, J. Grau, J. Keilwagen, S. Posch, and I. Grosse. DiffLogo: a comparative visualization of sequence motifs. BMC bioinformatics, 2015 Nov 17;16:387.<doi:10.1186/s12859-015-0767-x>.

Corresponding BibTeX entry:

  @Article{,
    author = {M. Nettling and H. Treutler and J. Grau and J. Keilwagen
      and S. Posch and I. Grosse},
    title = {DiffLogo: a comparative visualization of sequence
      motifs.},
    journal = {BMC bioinformatics},
    year = {2015},
    volume = {16},
    issn = {1471--2105},
    keywords = {logo, motif, sequence, tool},
    pmid = {26577052},
    url =
      {http://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-015-0767-x},
  }