Hurley, Patrick M., 1912-  Hurley, Patrick M., 1912- <br/><br/>
How old is the earth?. 

 - London :  Heinemann,  [1965 reprint] 
 - Science study series ;  5 .
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Radioactivity.<br/>Geological time.
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Earth.