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\bibitem{Li_etal2009} Li, C. - T., Chen, T. - J., Ni, T. - L., Lu, W. - C., Chiu, C. - P., Chen, C. - W., et al. (2009). Development of SIS mixers for SMA 400-520 GHz band. In \textit{Proc. 20$^{th}$ Int. Symp. Space Terahertz Technol.} (pp. 24--30).

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