Nobuyoshi Sato Minoru Udagawa Minoru Uehara Yoshifumi Sakai Reliability of a Distributed Search Engine for Fresh Information Retrieval in Large-Scale Intranet. 14-27 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2745&spage=14 2003 conf/ispa/2003 ISPA db/conf/ispa/ispa2003.html#SatoUUS03