References

• Beskin G.M., Shearer A., Redfern M., et al., 1998a, Nucl. Physics B (Proc. Suppl.) 69/1-3, 703

• Beskin G.M., et al., 1998b (in preparation)

• Fukugita M., Turner E.L., 1991, MNRAS 253, 99

• Hinshaw G., Krauss L.M., 1987, ApJ 320, 468

• Mao S., 1992, ApJ 389, L41

• Schneider P., Ehlers J., Falco E.E., 1992, Gravitational Lenses. Springer-Verlag, Berlin

• Wu X.P., 1989, A&A 214, 43

• Wu X.P., 1996, Fundam. Cosm. Phys. 17, 1