Twenhofel, William H.  <br/><br/>
Principles of invertebrate paleontology/  
William H. Twenhofel and Robert R. Shrock 
 - 2d ed. 
 - New delhi:   CBS publishing and distributors,   1987. 
 - xix, 816p.:  ill. 
<br/><br/> "A revised and enlarged edition of Twenhofel and Shrock, Invertebrate paleontology." 
<br/><br/>McGraw-Hill series in geology 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Invertebrates, Fossil
<br/><br/><label>LC Class. No.: </label>QE 770 TWE 1953