Durr, W.K. <br/><br/>
Keystone/ 
William K. Durr; Vivian O. Windley and Mildred C. Yates 
 - Boston:  Houghton mifflin,  1976. 
 - 576p.:  ill.;  24 cm. 
<br/><br/> Includes glossary 
<br/><br/><label>ISBN: </label>0395204135 
<br/><br/><label>Subjects--Topical Terms: </label>
<br/><br/><label>LC Class. No.: </label>DUCEPR6062.O86K4