Duke primer 

 - Colombo :  M.D. Gunasena,  1988 
 - 21p.;  18cm 
<br/><br/><label>ISBN: </label>9552101123 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social Sciences
<br/><br/><label>Dewey Class. No.: </label>372.6  / DUK