@article{MS09,
  author    = {M. Mundhenk and T. Schneider},
  title     = {The Complexity of Hybrid Logics over Equivalence Relations},
  journal   = {Journal of Logic, Language and Information},
  volume    = 18,
  number    = 4,
  pages     = {493-514},
  year      = 2009,
  ee        = {http://www.cs.manchester.ac.uk/%7Eschneidt/publ/ms09_jolli.pdf}
}