00321nam a2200121Ia 4500008004100000082000800041082001000049100002900059100002200088245005100110260001300161260002500174230118s9999||||xx |||||||||||||| ||und||  a621  bHEL/M  arobert arthurbhelliwell  bjoseph mayopettit 0aelectronic and radio engeering  fourth edition  aNEW YORK  bMC GRAW-HILL BOOK CO