@InProceedings{Areces2,
  author =       "Carlos Areces and Pascal Fontaine",
  title =        "Combining Theories: The Ackerman and Guarded
                 Fragments",
  booktitle =    frocos,
  year =         "2011",
  pages =        "40--54",
  ee =           "http://dx.doi.org/10.1007/978-3-642-24364-6_4",
  editor =       "Cesare Tinelli and Viorica Sofronie-Stokkermans",
  publisher =    "Springer",
  series =       lncs,
  volume =       "6989",
}