Éric Colin de Verdière Francis Lazarus Optimal Pants Decompositions and Shortest Homotopic Cycles on an Orientable Surface. 478-490 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2912&spage=478 2003 conf/gd/2003 Graph Drawing db/conf/gd/gd2003.html#VerdiereL03