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\bibitem{Darula_etal2000} Darula, M., Semenov, A. D., H{\"u}bers, H. - W., \& Schubert, J. (2000). Quasioptical high-T$_{c}$ superconductor Josephson mixer at terahertz frequencies. In \textit{Proc. 11$^{th}$ Int. Symp. Space Terahertz Technol.} (515).

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