00266nam a2200109Ia 4500008004100000041000800041082001800049100001600067245001900083260004600102300000800148211209s1974    xx            000 0 und d  aeng  a628.5 N74 PER  aPERKINS H C  aAIR POLLUTION   aNEW YORKbMCGRAW -HILL BOOK COMPANYc1974  a422