Spencer, Charles S. <br/><br/>
Drained fields at la tigra, venezuelan llanos :   A regional perspective. 

 - Washington, DC-US :   Society for American Archaeology,   1994. 
 - p.119-143 :   il 
 - trimestral 
 - Vol.5, no.2(Jun.1994) 
 - Latin American Antiquity ;   vol.5,no.2 .
 - Estados Unidos.   Society for American Archaeology. .