Kazemi, A. P., Sheikholeslami, S. M., Volkmann, L. (2011) The Roman (k,k)-domatic number of a graph Annales Mathematicae et Informaticae. 38. pp. 45-57. ISSN 1787-5021 (Print), 1787-6117 (Online)
Sheikholeslami, S. M., Volkmann, L. (2010) Signed (k,k)-domatic number of a graph Annales Mathematicae et Informaticae. 37. pp. 139-149. ISSN 1787-5021 (Print), 1787-6117 (Online)