Luis Quintano Irene Pimenta Rodrigues Managing Dialog in a Natural Language Querying System. 488-501 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2902&spage=488 2003 conf/epia/2003 EPIA db/conf/epia/epia2003.html#QuintanoR03