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\bibitem{Alfeld_etal2011} {\textquotedblleft}\textit{Optimization of mobile scanning macro-XRF systems for the in situ investigation of historical paintings}{\textquotedblright}. Alfeld M, Janssens K, Dik J, de Nolf W, van der Snickt G, Journal of analytical atomic spectrometry \textbf{26}, 899 (2011).   http://doi.org/10.1039/C0JA00257G

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