Contours of change. 

 - [Washington  For sale by the Supt. of Docs.  1970] 
 - xl, 366 p.  illus. 
 - Its Yearbook of agriculture  1970 .
 - Yearbook of agriculture (Washington, D.C. : 1926)  1970. .
<br/><br/><label>LCCN: </label>79609702 //r892 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture--United States.
<br/><br/><label>LC Class. No.: </label>S21  / .A35 1970 
<br/><br/><label>Dewey Class. No.: </label>338.1/0973