Geological Magagine. 

 - Hertford  Stephen Austin and Sons.  1956 
<br/><br/><label>ISSN: </label>4649 
<br/><br/><label>Standard No.: </label>
<br/><br/><label>LC Class. No.: </label>01GM         
<br/><br/><label>GPO Item No.: </label>1004649