Food production systems: Crops and their environment/plants as food 

 - Milton Keynes  Open University Press  1978 
 - 48p. 
<br/><br/><label>ISBN: </label> UKP 3.50 
<br/><br/><label>Source: </label> UKP 3.50 
<br/><br/><label>Dewey Class. No.: </label>641 FOO