000 00279nam a22001097a 4500
008 140104b xxu||||| |||| 00| 0 eng d
020 _a8170248655
050 _a507.2
100 _aGupta Naresh Kumar
245 _aResearch in teaching of science
260 _aNew Delhi
_bAPH
_c1997
999 _c329396
_d329396