Ban Van Den A W <br/><br/>
Agricultural Extension 

 -  London : Longman Scientific 1988. 
 - Better Farming Series No. 18 Fao Economic And Social Development Series No. 3/18 .
<br/><br/><br/>Eng 
<br/><br/><label>ISBN: </label>0 528 02883 3 (Pbk)