@inproceedings{DawarGroKreSch07,
  title = "Approximation Schemes for First-Order Definable Optimisation Problems",
  author = "Stephan Kreutzer Nicole Schweikardt Anuj Dawar and Martin Grohe",
  year = "2006",
  booktitle = "Logic in Computer Science (LICS)",
  pages = "411-420",
}