D.K.. <br/><br/>
Ancient Painting :   A Zigzag on a Bison Skull May be North America's Oldest Art. 

 - Oregon-XXU :   The Leach Publishing Group,   1999. 
 - p. 18 :   il. 
 - Bimestral 
 - Vol. I, no. 6, (Nov./Dec. 1999) 
 - Discovering Archaeology ;   no. 6 .
 - Estados Unidos.   The Leach Publishing Group. .
<br/><br/> Research & News. 
<br/><br/><br/>Art¡culo en inglés.