Yang, Z. Q., Hajenius, M., Baselmans, J. J. A., Gao, J. R., Klapwijk, T. M., Voronov, B., et al. (2005). Improved sensitivity of NbN hot electron bolometer mixers by vacuum baking. In _Proc. 16<sup>th</sup> Int. Symp. Space Terahertz Technol._ (pp. 222&ndash;225).