Gillion, Robert J. <br/><br/>
Classification and mapping of agricultural land for national water-quality assessment / 
by Robert J. Gilliom and Gail P. Thelin. 
 - United Stated:   U. S. Department of the Interior,   U. S. Geological Survey  [1997].  
 - vi, 70 p. :  tables, maps ;  28 cm. 
 -  1131 .
<br/><br/>Includes bibliographical references (p. 30). 
<br/><br/><label>ISBN: </label>0607868090 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agricultural mapping--United States<br/>Land use, Rular--United States<br/>Water quality--United States
<br/><br/><label>Dewey Class. No.: </label>333.760973