Mooi, Rich. <br/><br/>
Living and fossil genera of the Clypeasteroida (Echinoidea, Echinodermata) :  an illustrated key and annotated checklist / 
Rich Mooi. 
 - Washington, D.C. :  Smithsonian Institution Press,  1989. 
 - Smithsonian contributions to zoology ;  no. 488 .
<br/><br/>Bibliography: p. 50-51. 
<br/><br/><label>LCCN: </label>89600113 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sand dollars -- Identification.--Sand dollars -- Identification.
<br/><br/><label>LC Class. No.: </label>QL1  QL384.E2  / .S54 no. 488 
<br/><br/><label>Dewey Class. No.: </label>591 s  593.9/5 
<br/><br/><label>Gov. Doc. Class. No.: </label>SI 1.27:488