97% of edit
http://www.scielo.cl/scielo.php?pid=S0718-23762007000100020&script=sci_arttext
Article
Loading article revision...
Source
Loading possible copyvio source...
97% of edit
http://universum.utalca.cl/contenido/index-07-1/Garay.pdf
Article
Loading article revision...
Source
Loading possible copyvio source...