Shrock R R & Twenhofel W H <br/><br/>
Principles of Invertebrate Palaeontology .-Edn 2 

 - Edn 2 
 -  CBS Pub, N'Delhi 
 - pp 816;   23*15 
<br/><br/><label>Dewey Class. No.: </label>H6:(K1)/N87/B17521