1. P. Debye and E. Hückel, Phys. Z. 24, 185 (1923).
2. D. Brydges, Commun. Math. Phys. 58, 313 (1978).
3. See for example, “Elementary Excitations in Solids”, D. Pines, W.A. Benjamin, Inc., New York, 1964.
4. See for example, “Waves and Interactions in Solid State Plasmas”, P.M. Platzman and P.A. Wolff, Vol.135 of Solid State Physics, H. Ehrenreich, F. Seitz, D. Turnbull, Eds. Academic Press, New York, 1973.
5. J. Lindhard, K. Dan. Vidensk. Selsk, Mat.-Fys. Medd. 28 118 (1954).