Generation of C.W. stimulated sub-millimetre waves H. A. Gebbie, N. W. B. Stone, J. E. Chamberlain, W. Slough and W. A. Sheraton J. Chim. Phys., 64 (1967) 80-81 Published online: 28 May 2017 DOI: 10.1051/jcp/1967640080