000 00337nam a2200157Ia 4500
008 131111s9999 xx 000 0 und d
100 _aMangal,S.K.
245 _aTeaching of science
260 _aNew Delhi
260 _bArya
260 _c1990
300 _a183p.
650 _aEduction
_aTeaching
763 _a13421
942 0 0 _03
999 _c39939
_d39939