000 00254nam a22001217a 4500
003 OSt
082 _a544.1
_bHEL
100 _aHELFFERICH, FRIEDRICH
245 _aION EXCHANGE
260 _aNEW DELHI
_bMC GRAW HILL
_c1962
310 _a624
942 _2ddc
_cB
999 _c80221
_d80221