Heldman, Robert K. <br/><br/>
Information Telecommunications. Networks, Products, & Services / Robert K. Heldman 

 - Estados Unidos : McGraw-Hill, Inc. 
 - 386p. / 23.7 cm. 
<br/><br/><label>ISBN: </label>0-07-028040-1 
<br/><br/><label>LC Class. No.: </label>HE7631 H474 
<br/><br/><label>Dewey Class. No.: </label>384 H762i