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\bibitem{Kahl_etal2017} Kahl, O., Ferrari, S., Kovalyuk, V., Vetter, A., Lewes-Malandrakis, G., Nebel, C., et al. (2017). Spectrally multiplexed single-photon detection with hybrid superconducting nanophotonic circuits. \textit{Optica}, \textit{4}(5), 557--562.

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