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\bibitem{Abreu_etal2012} {\textquotedblleft}\textit{Electric field gradient calculations in ZnO samples implanted with $^{111}$In($^{111}$Cd)}{\textquotedblright}. Abreu Y, Cruz CM, van Espen P, P{\'e}rez C, Pi{\~n}era I, Leyva A, Cabal AE, Solid state communications \textbf{152}, 399 (2012).   http://doi.org/10.1016/J.SSC.2011.12.001

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