Hershler, Robert. <br/><br/>
Systematics of the North and Central American aquatic snail genus Tryonia (Rissooidea:Hydrobiidae) / 
Robert Hershler. 
 - Washington, D.C. :  Smithsonian Institution Press,  2001. 
 - 53 p. :  ill., maps ;  28 cm. 
 - Smithsonian contributions to zoology ;  no. 612 .
<br/><br/>Includes bibliographical references (p. 51-53). 
<br/><br/><label>LCCN: </label>2001-020792 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Tryonia--Classification.