00298nam a2200121Ia 450000500170000000800410001704100080005808200150006610000170008124500240009826000450012230000090016720260720174559.0260720s2005    xx            000 0 und d  aeng  a500.7 SINT  aSingh, Uttam  aTeaching of science  aNew DelhibCommonwealth Publishersc2005  a256p