00282nam a2200109Ia 4500100002000000654001800020245005900038260003900097082001600136300000800152546001200160  aHancock/john C   acommunication  aIntroduction to the principles of communication theory  bTata Mc Graw hillaNew Delhic1987  a621.38bHAN  a253  aENGLISH