Ivaylo Ilinkin Ravi Janardan Michiel H. M. Smid Eric Johnson Paul Castillo Jörg Schwerdt Approximating contact-area of supports in layered manufacturing. 91-94 2004 CCCG http://www.cccg.ca/proceedings/2004/21.pdf db/conf/cccg/cccg2004.html#IlinkinJSJCS04