00297nam a2200109 a 450000500170000002000150001708200190003210000220005124500690007326000240014230000210016620251203091527.0  a0442005032  a001.6443,bbea  aBeach, Robert, C.  aIntroduction to the Curves and surfaces of computer-aided design  aNew York: VNRc1991  axi,306p.c22 cm.