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\bibitem{Karpov_etal2009} Karpov A, Miller D, Stern JA, Bumble B, LeDuc HG, Zmuidzinas J. Broadband SIS mixer for 1 THz Band. In: Proc. 20$^{th}$ Int. Symp. Space Terahertz Technol.; 2009. p. 35.

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