1. Kinetic Theory of an Electron-Photon Gas
2. J. M. Jauch and F. Rohrlich,The Theory of Photons and Electrons(Addison-Wesley Publishing Company, Inc., Reading, Massachusetts, 1955), pp. 235–241.
3. Bose-Einstein statistics and degeneracy
4. On the Bose-Einstein Condensation
5. At sufficiently long wavelengths the free–free interaction becomes very strong and the Planck function is approached rapidly. Because of this the condensation phenomenon would be very difficult to achieve in practice.