Bretsky, Peter William,    1938- <br/><br/>
Upper Ordivician ecology of the Central Appalachians /  
O. W. Bret sky. 
 - New Haven :    Peabody Museum of Natural History, Yale University,    1970. 
 - viii, 150 p. :    ill., maps, 44 plates ;    26 cm. 
 - Yale University Peabody Museum of Natural History ;    Bullentin 34 .
<br/><br/>Includes bibliographyical references (p. 142-150). 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Paleoecology.<br/> Paleontology -- Ordovician.<br/> Paleontology -- Appalachian Mountains.
<br/><br/><label>Dewey Class. No.: </label>565.393 BRE