Joon-Kyung Seong Ku-Jin Kim Myung-Soo Kim Gershon Elber Intersecting a Freeform Surface with a Ruled or a Ringed Surface. 38-48 2004 conf/gmp/2004 GMP http://csdl.computer.org/comp/proceedings/gmp/2004/2078/00/20780038abs.htm db/conf/gmp/gmp2004.html#SeongKKE04