00345nam a2200133 a 450000500170000008200160001710000140003310000170004724500340006426000350009830000220013363000380015563000180019320251203090505.0  a577.27bTIV  aTivy, Joy  aO'Hare, Greg  aHuman impact on the ecosystem  aEdinburghbOliver & Boydc1981  a243p.c22 cm.bPB  aNature--Effect of human beings on  aHuman ecology