Sau Dan Lee Luc De Raedt An Efficient Algorithm for Mining String Databases Under Constraints. 108-129 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3377&spage=108 2004 conf/kdid/2004 KDID db/conf/kdid/kdid2004.html#LeeR04