Silverberg, Robert <br/><br/>
Clocks for the ages :  how scientists date the past / 
by Robert Silverberg 
 - New York :  MacMillan,  1971 
 - 238 p. :  ill. ;  21 cm. 
<br/><br/>Bibliography: p. 229-233 
<br/><br/><label>LCCN: </label>74-123134 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Time