Pennak, Robert W. <br/><br/>
Fresh-water invertebrates of the United States  protozoa to mollusca 
Robert W. Pennak. 
 - 3rd ed. 
 - New York  Wiley  c1989. 
 - xvi, 628 p.  ill. 
<br/><br/>Includes bibliographies and index. 
<br/><br/><label>ISBN: </label>0471631183 
<br/><br/><label>LCCN: </label>buc92000592  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freshwater invertebrates--United States.
<br/><br/><label>LC Class. No.: </label>QL141  / .P45 1989 
<br/><br/><label>Dewey Class. No.: </label>592.0973