000 00260nam a2200109Ia 4500
008 240421s9999 xx 000 0 und d
100 _aSingh, Uttam Kumar
245 0 _aScience Education
260 _aDelhi
_bCommonwealth
_c2007
300 _a319p.
942 _cBK
999 _c13172
_d13172