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\bibitem{Pentcheva_etal1991} {\textquotedblleft}\textit{Sur les processus, controlant le caract{\`e}re hydrochimique des eaux thermales profondes (Bulgarie M{\'e}ridionale)}{\textquotedblright}. Pentcheva E, Veldeman E, Van {\textquoteright}t dack L, Gijbels R, Comptes rendus de l{\textquoteright}Acad{\'e}mie bulgare des sciences \textbf{44}, 51 (1991)

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