deletions | additions       diff --git a/introduction_1.tex b/introduction_1.tex  index 9a246a7..17b9f75 100644  --- a/introduction_1.tex  +++ b/introduction_1.tex 
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\cite{erez-Flores_Gomez-Trevino_2005}  \cite{10.1190/1.1581067} \cite{http://library.seg.org/doi/abs/10.1190/1.1581067}  \cite{}