Pennak, Robert W <br/><br/>
Freshwater invertebrates of the United states 

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 - Ronald Press Co., New York  1953 
 - 769 
 - .
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<br/><br/><label>ISBN: </label>  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Invertebrates-- Zoology
<br/><br/><label>Dewey Class. No.: </label>592  PEN-F