Muhammad Alif Fitri Abdul Halim , <br/><br/>
ENSIKLOPEDIA EMPAT KHALIFAH :  ABU BAKAR, UMAR, UTSMAN, ALI / 
ALIF FITRI ; EDITOR BAHASA  : Nurul Jannah ; ILUSTRATOR : Cipu, Athool 
 - xxiv, 303 pages :  colour illustrations, photographs ;  28 cm 
<br/><br/><label>ISBN: </label>9789673888214  RM 116.10 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Caliphs
<br/><br/><label>Dewey Class. No.: </label>297.61