003670000a22000970004500060000800000082001400008245012700022260006600149300000800215650004600223  a100  a631.7 HEA  aHeadwaters control and use : a summary of fundamental principles and their application in the conservation and utilization  aWashington D.C., Soil conservation service and forest service  a261  aHeadwaters control - use/ water behaviour