Pennak, Robert W. (Robert William) <br/><br/>
Fresh-water invertebrates of the United States. 

 - New York,  Ronald Press Co.  [1953] 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>LCCN: </label>52012522 /L/r86 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freshwater invertebrates -- United States.--Freshwater invertebrates -- United States.
<br/><br/><label>LC Class. No.: </label>QL141  / .P45 
<br/><br/><label>Dewey Class. No.: </label>592