Exchange systems in prehistory / 
edited by Timothy K. Earle, Jonathan E. Ericson 
 - New York :  Academic Press,  1977 
 - 274 p. :  ill. ;  25 cm. 
<br/><br/> Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>0122276507 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Commerce, Prehistoric--Addresses, essays, lectures