Smith, James Perrin <br/><br/>
Lower Triassic ammonoids of North America 

 - Washington, D.C.  U.S. Geological Survey  1932 
 - pp. 1-198  láms. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>AMMONOIDEA<br/>TRIASICO
<br/><br/><label>Subjects--Geographic Terms: </label><br/>ESTADOS UNIDOS