Changhe Tu Wenping Wang Jiaye Wang Classifying the Nonsingular Intersection Curve of Two Quadric Surfaces. 23-32 2002 conf/gmp/2002 GMP http://csdl.computer.org/comp/proceedings/gmp/2002/1674/00/16740023abs.htm db/conf/gmp/gmp2002.html#TuWW02