00509nam a2200169Ia 4500008004000000020001800040082001300058100001700071245002500088260003300113300000800146650002100154690001800175906001100193999001700204952011800221210210b1992   xxu||||| |||| 00| 0 eng d  a81 7041 632 9  a507 YADT  aYADAV (M S).  aTeaching of science.  aNDbAnmol Publicationsc1992  a240  aScience teaching  aPure Sciences  a051219  c99932d99932  001040708ScienceaALbALcScienced2021-02-17g50.00l0o507 YADTp051219r2021-02-17 00:00:00w2021-02-17yBK