Reference:
  Author: Deorowicz, S., Kokot, M., Grabowski, Sz., Debudaj-Grabysz, A.
  Title: KMC 2: Fast and resource-frugal k-mer counting
  Journal: Bioinformatics
  Year: 2015
  Volume: 31
  Number: 10
  Pages: 1569-1576
  DOI: 10.1093/bioinformatics/btv022
  PMID: 25609798
  URL: http://bioinformatics.oxfordjournals.org/content/31/10/1569
