Lower Triassic ammonoids of North America / 
by James Perrin Smith. 
 - Washington :  U.S. Gov't. Print. Off.,  1932. 
 - v, 199 p. :  ill., map, 81 plates ;  29 cm. 
 - Geological Survey (U.S.). Geological Survey professional paper ;  no. 167 .
 - Geological Survey professional paper ;  no. 167. .
<br/><br/> At head of title: United States Department of the Interior. 
<br/><br/>Bibliography: p. 4-6. 
<br/><br/><label>LCCN: </label>gs 32000180  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ammonoidea.<br/>Paleontology--North America.<br/>Paleontology--Triassic.
<br/><br/><label>LC Class. No.: </label>QE75  / .P9 no. 167 
<br/><br/><label>Gov. Doc. Class. No.: </label>I 19.16:167