@ARTICLE{tkde06-KST,
  AUTHOR  = {Manolis Koubarakis and Spiros Skiadopoulos and Christos Tryfonopoulos},
  TITLE   = "{Logic and Computational Complexity for Boolean Information Retrieval}",
  JOURNAL = "{IEEE Transactions on Knowledge and Data Engineering}",
  VOLUME  = {18},
  NUMBER  = {12},
  PAGES   = {1659--1666},
  YEAR    = {2006},
}