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\bibitem{Ruhle_etal1984} Ruhl{\'e}, C., Deufel, J., Keiz, G., Kindle, T., Klein, M., L{\"o}ffler, H., et al. (1984). \textit{Die Bodensee-Seeforelle -- Probleme und Probleml{\"o}sungen} (Vol. 37).

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