@Article{LuWaWo-IandC-06,
  author = 	 {C. Lutz and D. Walther and F. Wolter},
  title = 	 {Quantitative Temporal Logics: {{\sc PSpace}} and below},
  journal = 	 {Information and Computation},
  year = 	 2006,
  volume = 	 {205},
  number =       {1},
  pages =        {99--123}
}