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\bibitem{Langerak_etal1991} {\textquotedblleft}\textit{Far-infrared magneto-optical studies of the polaron effect in low dimensional GaAs-(Ga,Al)As structures}{\textquotedblright}. Langerak CJGM, Singleton J, Perenboom JAA, Devreese JT, Barnes DJ, Nicholas RJ, Huant S, Harris JJ, Foxon CT, Etienne B, Peeters FM, Physica scripta \textbf{T39}, 308 (1991).   http://doi.org/10.1088/0031-8949/1991/T39/047

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