Covey Stephen R. <br/><br/>
Principle - Centered Leadership / Stephen R. Covey. 

 -  New York : Simon & Schuster 1991 
 - 334 P. : ILL. 22 CM. 
 -  0 .
<br/><br/><br/>ENG 
<br/><br/><label>ISBN: </label>0671792806 (Pbk.)