Miguel Granados Peter Hachenberger Susan Hert Lutz Kettner Kurt Mehlhorn Michael Seel Boolean Operations on 3D Selective Nef Complexes: Data Structure, Algorithms, and Implementation. 654-666 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2832&spage=654 2003 conf/esa/2003 ESA db/conf/esa/esa2003.html#GranadosHHKMS03