Penny, David Harry,  1930- <br/><br/>
The transition from subsistence to commercial family farming in North Sumatra  [microform] / 
by David Harry Penny 
 - Ann Arbor, Mich. :  University Microfilms International,  1965 
 - 1 microfilm reel :  positive ;  35 mm. 
<br/><br/>Thesis (Ph.D) - Cornell University, 1964 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture--Indonesia
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Indonesia--Agriculture