Thomas Schmidt Jens Stoye Quadratic Time Algorithms for Finding Common Intervals in Two and More Sequences. 347-358 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3109&spage=347 2004 conf/cpm/2004 CPM db/conf/cpm/cpm2004.html#SchmidtS04