Estela Saquete Rafael Muñoz Patricio Martínez-Barco José Luis Vicedo González Comparison and Evaluation of Two Approaches of a Multilayered QA System Applied to Temporality. 91-102 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3230&spage=91 2004 conf/tal/2004 EsTAL db/conf/tal/estal2004.html#SaqueteMMG04