Denis Bertrand Olivier Gascuel Topological Rearrangements and Local Search Method for Tandem Duplication Trees. 374-387 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3240&spage=374 2004 conf/wabi/2004 WABI db/conf/wabi/wabi2004.html#BertrandG04