00257nam a2200109Ia 4500008004100000041000800041082001200049100001700061245002500078260003600103300000800139211209s1969    xx            000 0 und d  aeng  aMAR/NEL  aMARSHALL W T  aSTRUCTURES SI UNITS   aLONDONbE L B S & PITAMANc1969  a470