00285nam a2200109Ia 4500008004100000020001800041082001800059100002200077245004200099260002500141300000900166210430s9999    xx            000 0 und d  a1-59370-073-3  a658.26 S447 G  aDr. Duncan Seddon  aGas Usage & Value cDr. Duncan Seddon  aUSAbPenn Wellc2006  a328p