Walker, Bruce I. <br/><br/>
Computer security and protection structures   
by Bruce J. Walker, Ian F. Blake 
 - Stroudsburg  Dowden. Hutchinson & Ross  1977 
 - ix, 142p. 
<br/><br/><label>ISBN: </label>0879332476 
<br/><br/><label>Dewey Class. No.: </label>005.8  / N77