Raana, Irfan Mahmud <br/><br/>
Y Economic system under Umar the Great 
by Irfan Mahmud Ra'ana 
 - 2nd. ed. 
 - Lahore  Sh. Muhammad Ashraf  1977 
 - 165 p. ; 22 cm. 
<br/><br/> Includes index.  ( A treatise on Muslim Economy in Early Seventh Century ) 
<br/><br/>p.155-157. 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Islamic Empire--Economic conditions