Agricultural / biological subject category list 
/por E.U.A. National Agricultural Library 
 - Washington, D.C. :  National Agricultural Library,  1965 
 - 48 p. 
<br/><br/><label>LCCN: </label>100346 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agricultura--Tesauros.<br/>Biología.<br/>Encabezamientos de materia--Agricultura.