Kawamura, J., Blundell, R., Tong, C. - Y. E., Gol'tsman, G., Gershenzon, E., & Voronov, B. (1995). NbN hot-electron mixer measurements at 200 GHz. In _Proc. 6th Int. Symp. Space Terahertz Technol._ (pp. 254–261).