Anwering Recursive Queries under Keys and Foreign Keys is Undecidable Diego Calvanese and Riccardo Rosati   View Paper (PDF)   Return to Regular Papers BIBTEX @inproceedings       {DBLP:conf/krdb/CalvaneseR03,   author    = {Diego Calvanese and                 Riccardo Rosati},    booktitle = {KRDB},    title     = {Anwering Recursive Queries under Keys and Foreign Keys is Undecidable.},    year      = {2003},    url       = {db/conf/krdb/krdb2003.html#CalvaneseR03},    ee        = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-79/calv-rosa-KRDB-2003.pdf},    crossref  = {conf/krdb/2003},    bibsource = {DBLP, http://dblp.uni-trier.de}  } ©2004 Association for Computing Machinery