00290nam a2200109Ia 450000500170000000800410001708200120005810000210007024500400009126000410013130000080017220260224041017.0260224s9999||||xx |||||||||||||| ||und||  a909 CLA  aClayton, A.M.H.  0aSustainability : a systems approach  aLondon: Earthscan Publicationsc1996  a258