1. Cf. C.G. Darwin, Proc. Roy. Soc. London (A), 136, 36 (1932).
2. These relations can be found in a somewhat different form (four-dimension) in P. Jordan and W. Pauli, Z. Phys. 47, 151 (1927) and in the form given here in W. Heisenberg and W. Pauli, ibid., 56, 1 (1927).
3. Cf. L. Landau and R. Peierls, Z. Phys. 62, 188 (1930).
4. A discussion on the introduction of the quantities F and F * for avoiding the zero-point energy can be found in L. Rosenfeld and J. Solomon, Journ. de Phys. Series 7, 2, 139 (1931) and also in J. Solomon, Doctoral Thesis, Paris (1931). The C.R. between i F and F* given in these references arc, incorrect, since they are not compatible with the conditions, div
$$\vec F = 0$$
and div
$$\vec F* = 0$$
.
5. Cf. L. Landau and R. Peierls, Z. Phys. 69, 56 (1931) in particular, Secs. 3 and 4; W. Heisenberg, The Physical Principles of Quantum Theory, loc. cit., Chapter 3, Sec. 2.