Humic and fulvic acids  isolation, structure and enviromental role 
Jeffrey S. Gaffney, Nancy A. Marley, Sue B. Clark 
 - xii; 338 páginas 
 - ACS Symposium 651 .
<br/><br/><label>ISBN: </label>084123468X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Edafología
<br/><br/><label>Dewey Class. No.: </label>631.417  / GAF 1996