Roman k-domination in graphs
J. Korean Math. Soc. 46 (2009), 1309--1318.
BibTex references
@Article\{KV09,
author = "Kaemmerling, K. and Volkmann, Lutz",
title = "Roman k-domination in graphs",
journal = "J. Korean Math. Soc.",
volume = "46",
pages = "1309--1318",
year = "2009",
}