Understanding data communications /  [Book] / 
written by George E. Friend ... [et al.] ; with contributions by Gerald Luecke, managing editor, Charles W. Battle, editor. 
 - 2nd ed. /  revised by Gilbert Held. 
 - Indianapolis, Ind. :  H.W. Sams,  c1988. 
 - iv, 291 p. :  ill. ;  23 cm. 
 - Sams understanding series .
<br/><br/> Includes index. 
<br/><br/> All. 
<br/><br/><label>ISBN: </label>0672272709 (pbk.) : 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems.
<br/><br/><label>Dewey Class. No.: </label>621.382