deletions | additions       diff --git a/introduction_1.tex b/introduction_1.tex  index ad76a38..601be1a 100644  --- a/introduction_1.tex  +++ b/introduction_1.tex 
...
\cite{Oliveira_Jr_Barbosa_Silva_2011}  \cite{} \cite{10.1190/1.3524286}  \cite{} \cite{10.1190/1.3555078}  \cite{}