@Article{klarlund99:_algor_onlin_bdd_refin,
  author = 	 {Klarlund, Nils},
  title = 	 {An $n \log n$ Algorithm for Online {BDD} Refinement},
  journal = 	 {Journal of Algorithms},
  year = 	 1999,
  volume =	 32,
  pages =	 {133-154},
  note =	 {Abbreviated version in: ``Computer Aided Verification,'' 
CAV '97, Haifa, Israel, 1997, LNCS 1254},
}