Mueller, David K. <br/><br/>
Nutrients in the nation’s waters :  too much of a good thing? / 
by David K. Mueller and Dennis R. Helsel ; graphic edited by Mary A. Kidd.. 
 - United States:   U. S. Geological Survey,   U. S. Department of the Interior  [1996].  
 - 24 p. :  col. ill., col. maps ;  28 cm. 
 -  1136 .
<br/><br/>Includes bibliographical references (p. 22). 
<br/><br/><label>Subjects--Uniform Titles: </label><br/>Nutrient pollution of water
<br/><br/><label>Dewey Class. No.: </label>628.168