1. P. Baekler, F. W. Hehl andE. W. Mielke: inProceedings of the II Marcel Grossmann Meeting on General Relativity, edited byR. Ruffini (North-Holland, Amsterdam, 1982), p. 413.
2. P. Baekler andE. W. Mielke:Phys. Lett. A,113, 471 (1986).
3. E. W. Mielke:Geometrodynamics of Gauge Fields (Akademie-Verlag, Berlin, 1987), pp. 85–91.
4. P. Baekler andM. Gürses:Lett. Math. Phys. (to appear).
5. M. Gürses:Phys. Lett. A,10, 388 (1984).