Walker, Bruce J <br/><br/>
Computer security and protection structures / 
Bruce J. Walker, Ian F. Blake 
 - Dowden :  Hutchinson & Ross, Stroudsburg, Pa.,  1977 
 - ix, 142 p, ;  25 cm. 
<br/><br/>Includes bibliography and index 
<br/><br/><label>ISBN: </label>0879332476 
<br/><br/><label>LCCN: </label>76-11767 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computers--Access control<br/>Electronic data processing departments--Security measures