Cisne, J L <br/><br/>
Geograpehic variation and episodic evolution in an ordovician trilobite.  [electronic resource] 

 -  Science (New York, N.Y.)  Aug 1980 
 - 925-7 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0036-8075 
<br/><br/><label>Standard No.: </label>10.1126/science.209.4459.925  doi