00253nam a2200109 a 450000500170000002000150001708200150003210000160004724500230006326000390008630000180012520251203091913.0  a8122001246  a519.4bGup  aGupta, B.D.  aNumerical analysis  aNew DelhibKonark Publishersc1989  a585p.c21 cm.