1. Montroll, E. W. & West, B. J. in Fluctuation Phenomena (eds Montroll, E. W. & Lebowitz, J. L.) (North-Holland Personal Library, 1987).
2. Montroll, E. W. & Shlesinger, M. F. in Nonequilibrium Phenomena II. From Stochastics to Hydrodynamics (eds Lebowitz, J. L. & Montroll, E. W.) 1–121 (North-Holland, Amsterdam, 1984).
3. Dvoretzky, A. & Erdös, P. in Proc. 2nd Berkeley Symp. 33 (University of California, Berkeley, 1951).
4. Vineyard, G. H. J. math. Phys. 4, 1191–1193 (1963).
5. Beeler, R. J. & Delaney, J. A. Phys. Rev. A130, 962–966 (1963).