@Article{Ratschan:03,
  author = 	 {Stefan Ratschan},
  title = 	 {Convergent Approximate Solving of First-order Constraints by Approximate Quantifiers},
  journal = 	 {ACM Transactions on Computational Logic},
  volume =       {5},
  number =       {2},
  pages =        {264--281},
  year = 	 2004
}