Islamic spirituality :  foundations / 
edited by Seyyed Hossein Nasr 
 - London :  Routledge & Kegan Paul,  1987 
 - 450 p. :  ill. ;  25 cm. 
 - World spirituality  19 .
<br/><br/>p. 428-439 
<br/><br/><label>ISBN: </label>0710210973 
<br/><br/><label>LCCN: </label>86-019935 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Islam