1. Bengtzelius, U., Götze, W., Sjögren, L.: J. Phys. C17, 5915 (1984)
2. Leutheusser, E.: Phys. Rev. A 29, 2765 (1984)
3. Extended reviews and references can be found in: Götze, W.: In: Liquids, Freezing and the Glass Transition, p 287; Hansen, J.P., Levesque, D., Zinn-Justin, J. (eds) Les Houches 1989 Amsterdam: North-Holland 1991; Götze, W., Sjögren, L.: Rep. Prog. Phys. 55, 251 (1992);
4. Schilling, R.: In: Disorder Effects on Relaxational Processes, p 193; Richert, R., Blumen, A. (eds) Berlin: Springer 1994
5. Bengtzelius, U.: Phys. Rev. A 34, 5059 (1986)