Johnson, D. Gale <br/><br/>
Grain Yields and the American Food Supply  An analysis of yield changes and possibilities 

 - London  The University of Chicago  1962 
 - 146p. 
<br/><br/><label>Subjects--Uniform Titles: </label><br/>Food supply
<br/><br/><label>Dewey Class. No.: </label>338.1973  / J50G