Clark, Colin. <br/><br/>
The economics of subsistence agriculture / 
by Colin Clark and Margaret Haswell. 
 - 4th ed. 
 - London :  Macmillan,  1970. 
 - xiv, 267 p. :  ill. 
<br/><br/><label>ISBN: </label>0333116585 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture--Economic aspects.