@article{Volkmann11-1,
  title = {Signed domination and signed domatic numbers of digraphs},
  author = {Lutz Volkmann},
  year = {2011},
  url = {http://www.uz.zgora.pl/discuss/gt/31_3/gt31-773.htm},
  researchr = {https://researchr.org/publication/Volkmann11-1},
  cites = {0},
  citedby = {0},
  journal = {Discussiones Mathematicae Graph Theory},
  volume = {31},
  number = {3},
  pages = {415-427},
}