@Article{LuArHoSaJAIR04,
  author =       "C. Lutz and C. Areces and I. Horrocks and U. Sattler",
  title =        "Keys, Nominals, and Concrete Domains",
  journal =      "Journal of Artificial Intelligence Research",
  year = 	 {2004},
  note =         "to appear"
}