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\bibitem{Gerecht_etal1999} Gerecht E, Musante CF, Jian H, Zhuang Y, Yngvesson KS, Dickinson J, et al. Improved characteristics of NbN HEB mixers integrated with log-periodic antennas. In: Proc. 10$^{th}$ Int. Symp. Space Terahertz Technol.; 1999. p. 200--7.

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