Britannica Ready Reference Encyclopaedia, Vol.06: La Brea Tar Pits to Modernism 

 -  Encyclopaedia Britannica (India) Private Limited, New Delhi  2005 
 - 276 
<br/><br/><label>Subjects--Topical Terms: </label><br/>General encyclopedic works
<br/><br/><label>Dewey Class. No.: </label>R 030  BRI.06