Principles of invertebrate paleontology/ 
Shrock, Robert R. 
 - 2nd ed. 
 - New Delhi:  CBS,  2005. 
 - 816 p. 
<br/><br/><label>ISBN: </label>8123912188 
<br/><br/><label>Dewey Class. No.: </label>562  / SHO/P