Subterahertz spectroscopy at He-3 temperatures

D. N. Basov, S. V. Dordevic, E. J. Singley, W. J. Padilla, K. Burch, J. E. Elenewski, L. H. Greene, J. Morris, R. Schickling.
Subterahertz spectroscopy at He-3 temperatures
Review of Scientific Instruments 74, 4703 (2003)