00305nam a2200121Ia 450000500170000000800410001704100080005808200150006610000150008124500400009626000380013630000090017420260720174538.0260720s2005    xx            000 0 und d  aeng  a372.8 SINT  aSingh, U K  aTeachning of enviournmental science  aNew DelhibA P H Publishingc2005  a366p