1. J. M. Raimond, P. Goy, M. Gross, C. Fabre, and S. Haroche, Phys. Rev. Lett. 49: 117 (1982).
2. D. Meschede, H. Walther, and G. Müller, Phys. Rev. Lett. 54: 551 (1985).
3. H. Walther, “Non-classical radiation from one-atom oscillators”. This meeting.
4. P. Meystre, “Generation and detection of sub-Poissonian fields in micromasers”. This meeting.
5. B. Yurke, “Squeezing thermal microwave radiation”. This meeting. Also B. Yurke, P. G. Kaminsky, R. E. Miller, E. A. Whittaker, A. D. Smith, A. H. Silver and R.W. Simon,“Observation of 4.2K equilibrium noise squeezing via a Josephson-parametric amplifier”. To be published.