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\bibitem{Claes_etal1999} {\textquotedblleft}\textit{Determination of silicon in organic matrices with grazing-emission X-ray fluorescence spectrometry}{\textquotedblright}. Claes M, van Dyck K, Deelstra H, Van Grieken R, Spectrochimica acta: part B : atomic spectroscopy \textbf{54}, 1517 (1999).   http://doi.org/10.1016/S0584-8547(99)00098-1

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