Pascal Berthomé Madiagne Diallo Afonso Ferreira Generalized Parametric Multi-terminal Flows Problem. 71-80 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2880&spage=71 2003 conf/wg/2003 WG db/conf/wg/wg2003.html#BerthomeDF03