Krugman, Paul. <br/><br/>
'Poverty can be very creative' :  Lithium. 

 - La Paz-BO   Grupo Express Press  2013 
 - p. 14-15 :   il.   
 - Irregular 
 - No. 26(Mar 2013) 
 - Bolivan Express. Reinventig Progress ;   no. 26 .
 -   Grupo Espress Press.   .