1. T. H. Boyer,Phys. Rev. D 11, 790 (1975);11, 809 (1975). See also the remarkable paper by T. W. Marshall,Proc. R. Soc. London Ser. A 273, 475 (1963).
2. L. de la Peña, inStochastic Processes Applied to Physics and Other Related Fields, B. Gomezet al., ed. (World Scientific, Singapore, 1982), p. 428. See also L. de la Peña and A. M. Cetto,Found. Phys. 12, 1017 (1982) and P. W. Milonni,Phys. Rep. 25, 1 (1976).
3. P. W. Milonni, inThe Quantum Vacuum: An Introduction to Quantum Electrodynamics (Academic, Boston, 1994).
4. See S. Bergia, P. Lugli, and N. Zamboni,Ann. Found. Louis de Broglie 5, 39 (1980) for a commented translation of the Einstein and Stern 1913 paper. See also P. W. Milonni and M. L. Shih,Am. J. Phys. 59, 684 (1991) for interesting comments concerning the zero-point energy in early quantum theory.
5. W. Nernst,Ver. Deutsch. Phys. Ges. 18, 83 (1916).